It was a great time being back in Ottawa, visiting with friends from my old neighborhood and also spoiling my Daughters two cats.

However on the “Radio side” of things …. not so good

The plans were that I would be able (weather permitting) continue to control my hour on the Trans Provincial Net while away. It seemed that “Mother Nature” had different ideas. Most days rain or the threat of rain kept me from heading over to the park.

Above pic showing where the park was and the route I took

As I mentioned in a previous post…. there was a local (non-POTA) park within walking distance to operate from. It was a local sports field and had some bleachers for when the crowds came for Junior Soccer/Football and or Rugby…

Below pic showing how I set up at the park

Although the operating position was excellent there was NO PROTECTION from the elements which in my case meant rain.

I was able to wrap my MFJ mast to one of the bleachers and stretch the end of the EFHW antenna to the other bleacher and it did work like a charm. Signal reports were great considering I was running 50w into the antenna

So for 1 out of a potential 5 operating days it was fun and dry. Walking home with the gear safely packed in the backpack “Mother Nature” paid a short visit.

I also managed to activate CA1515 and CA1516 using my Xiegu X5105 along with a 29 foot wire (supported by the same mast mentioned earlier) with a 9:1 unun, a 17 foot counterpoise with a choke on the radio end of the coax. Jose VA3PCJ was nice enough to offer me a ride there and back. I activated the parks using SSB and VA3PCJ activated the same parks using CW and his KX3.

For Jose’s version of the park activation click HERE

I am expecting to be returning to Ottawa in Mid-January 2025 for another visit with my GrandKits and like last years winter visit there will be a car to keep me warm and dry.

73bob

Figure 1: Power/VSWR meter using ИН-13 neon bar-graph indicators. Click on the image for a larger version

In Part 1 I laid out the requirements of the ИН-13-based neon bar-graph VSWR/power meter.  Admittedly, this is a "buy cool, old tech and figure out what project might use it" scenario - but having one tube always showing the forward power and the other tube showing either reverse power of calculated VSWR was the goal.

Figure 2: ИН-13 tubes in the raw. It is up to the constructor to determine how best to mount these tubes - and how to connect them to the circuit. Figure 3 shows how flexible wires were attached as the wires on the tubes themselves are very easily broken! Click on the image for a larger version.

In preparing the tubes for mounting I trimmed the wire leads and soldered flexible wires to them, covering them with "hot melt" (thermoset) adhesive to passivate the connection, making them relatively durable:  The original wires will NOT tolerate much flexing at all and are likely to break off right at the glass "pinch" - which would make the tube useless.   Figure 3 shows how the leads were encapsulated - the thermoset adhesive being tinted with a permanent marker - mainly to add a bit of color.

Laser-cut sheets and markings

Figure 3: Close-up of the "hot-glue" covered wire attachments for the ИН-13 tubes.  Also visible are the black wire loops holding them in place and the laser-edged markings on the acrylic. Click on the image for a larger version.

In looking at Figure 1 and 3 you will also notice that there are scales indicating the function and showing scale graduations and the associated numerical values.  I'm fortunate to have a friend (also an amateur radio operator) who has a high-power laser cutter and it was easy to lay out the precise dimensions of the acrylic sheets and also have it cut the holes for the mounting screws in the corners as well.

While it takes a bit of laser power to cut the sheets, a far lower power setting will ablate the surface, yielding a result not unlike surface engraving and when lit from the edges, these ablations will light up with the rest of the sheet remaining pretty dark:  A total of four sheets were cut and "engraved" in this way:  The front sheet for "VSWR" and its markings, the middle sheet for "Reverse Power" and the rear acrylic sheet for "Forward Power".  It was possible to arrange the lettering so that only "VSWR" and "Reverse Power" were atop each other but in subdued light - and with a bit of darkened plastic in front of the display - the markings on the un-lit sheet are practically invisible.  The fourth sheet mentioned was left blank, being the protective cover. 

Edge lighting

Edge-lit displays go back decades - and the idea likely goes back centuries where it was observed that imperfections in glass (later, plastic) would be visible if the substrate was illuminated from the edge.  Since the early-mid 20th century, one could find a number of edge-lit indicators - usually in some sort of test equipment of industrial displays - but they occasionally showed up in the consumer market - usually acrylic or similar with the markings engraved with a rotary tool or - as may be done nowadays, a laser.

While incandescent lamps would have been used in the past, LEDs are the obvious choice these days and for this I selected some "high brightness" LEDs to light the edges of the engraved acrylic sheets.  For the "Forward Power" sheet - which would be that which was always illuminated in use - I chose white while using Green for VSWR and Blue for Reverse Power.  I'd considered Yellow and Red, but discarded the former as it might appear too much light the white under some conditions and past experience has reminded me that - particularly in a dark room - the human eye can't see or focus on fine detail on red objects very easily.

Figure 4: Six LEDs are epoxied to the edge to evenly light the laser- etched markings in the acrylic sheet.  The faces of the LEDs were filed flat to facilitate bonding and improve efficiency. Click on the image for a larger version.

Figure 4 shows some details as to how the edge lighting is accomplished.  Six equally-spaced LEDs were epoxied to the bottom edge of the display, arranged to be nearly the width of the engraved text.  In writing this entry I observed that photographing edge-lit displays such as this is nearly impossible owing to the variations in illumination (e.g. it's difficult to take pictures of very bright objects in the dark!) but the effect is very even as viewed by the human eye.

The six LEDs were connected as two series strings of three LEDs:  As each LED requires about three volts - and I have only a 12 volt power source - doing so requires only a bit more than nine volts to power the LED arrays.  As the green and white LEDs are also silicon nitride based as well, they take similar voltages.

Not readily apparent from Figure 4 is the fact that the LEDs were modified slightly.  As we are trying to interface a standard T1-3/4 LED to the flat edge of a plastic sheet, it's apparent that the rounded, focused lens makes this physically difficult.  To mitigate this, the top of the LED was flattened with a file and the clear epoxy was removed to just above the light emitting die.  The result of this is that a flat surface is mated to another flat surface for a physically stronger bond and a more efficient coupling of light and a bit of the LED's original directivity in the form of the "lens" is removed from the equation. 

Just prior to mounting the acrylic sheets in the "stack up" some black electrical tape was applied.  This tape was put on both sides of the sheet, extending just above the bottom edge, to reduce the glare from the LEDs and to minimize the possibility of this light coupling into the adjacent sheet.

Mounting the tubes and sheets

As can be seen from Figure 3, the tubes are held in place with loop of solid-core insulated wire - the holes mounting them also "drilled" with the laser.  The "stack-up" of acrylic sheets and the tubes - both of which were mounted on "VSWR" acrylic layer - is held together using 6-32 brass machine screws and spacers with a piece of 1/4" (5.2mm) plywood covered with black felt for the back to provide contrast.

The box and base

As can be seen from figure 1, the entire unit is in a wooden base:  The same friend with the laser cutter also had some scraps of red oak and a simple base was made, decorated with an ogee cut around the perimeter with the router while atop it a simple box with mitered corners - facing at a slight upward angle - in which the display and electronics reside.  On the base itself are two buttons:  One switches between VSWR and Reverse Power and the other between peak and average readings.  These switches have other functions as well, which will be discussed in the third installment when the final circuit and internal workings of the software is discussed.

* * * * *

This page stolen from ka7oei.blogspot.com

[END]

It was a great time being back in Ottawa, visiting with friends from my old neighborhood and also spoiling my Daughters two cats.

However on the “Radio side” of things …. not so good

The plans were that I would be able (weather permitting) continue to control my hour on the Trans Provincial Net while away. It seemed that “Mother Nature” had different ideas. Most days rain or the threat of rain kept me from heading over to the park.

Above pic showing where the park was and the route I took

As I mentioned in a previous post…. there was a local (non-POTA) park within walking distance to operate from. It was a local sports field and had some bleachers for when the crowds came for Junior Soccer/Football and or Rugby…

Below pic showing how I set up at the park

Although the operating position was excellent there was NO PROTECTION from the elements which in my case meant rain.

I was able to wrap my MFJ mast to one of the bleachers and stretch the end of the EFHW antenna to the other bleacher and it did work like a charm. Signal reports were great considering I was running 50w into the antenna

So for 1 out of a potential 5 operating days it was fun and dry. Walking home with the gear safely packed in the backpack “Mother Nature” paid a short visit.

I also managed to activate CA1515 and CA1516 using my Xiegu X5105 along with a 29 foot wire (supported by the same mast mentioned earlier) with a 9:1 unun, a 17 foot counterpoise with a choke on the radio end of the coax. Jose VA3PCJ was nice enough to offer me a ride there and back. I activated the parks using SSB and VA3PCJ activated the same parks using CW and his KX3.

For Jose’s version of the park activation click HERE

I am expecting to be returning to Ottawa in Mid-January 2025 for another visit with my GrandKits and like last years winter visit there will be a car to keep me warm and dry.

73bob

Wow... it's been way too long since my last post on this blog.

Disclaimer - In what I’m describing in this post, to avoid any confusion that I’m trying to claim that any of this involves Amateur Radio, I decided to call this experiment Meadow Day (1). 

Meadow Day 2023 Experiment - Overview

In Zero Retries 0104 Request to Send, Starlink Field Day? I mentioned casually:

Now that I’m a Starlink customer, I consider communications with little terrestrial infrastructure required to be a mostly solved problem, especially when you factor in the increasingly capable battery plus solar units providing power. The combination of the Starlink hardware, battery plus solar, and Starlink subscription isn’t cheap… but it’s amazingly capable… in fact, a paradigm change. But that’s a story for a future issue of Zero Retries. Teaser - Imagine an app that ran on a laptop or Raspberry Pi that connected to another (roaming) Starlink terminal (on battery power), transferred a large file, and then “logged the contact”?

As I woke up yesterday morning (2023-06-24), I thought briefly about ARRL Field Day (2). Because of recent family events, I haven’t been able to devote much time to preparation for Field Day activities, and couldn't devote the entire day to attending a local Field Day event. But I did have a few hours… and the idea came to me fully formed, that I actually could try out “Starlink Field Day” as a proof of concept. I decided that the goal would be to "work" a few Amateur Radio Operators using broadband Internet connectivity via Starlink.

Again - to avoid any confusion that what I'm describing here involves Amateur Radio, I decided to call this experiment Meadow Day. 

Right after morning coffee time I assembled the various pieces I would need and hauled them out of N8GNJ Labs into the middle of my large yard, and started plugging them all together. To my delight… but not quite surprise, it all worked.

What I wanted to test out was, was it practical to “deploy” a Starlink system in “emergency” conditions - on battery power? Short answer, Yes. Even though it was overcast, the solar panel output at least 20 watts, and when there were “widely scattered sunbursts” the solar panel put out as much as 80 watts. The Starlink required typical 60 watts, so the battery on the EB3A trended down slowly.

It worked surprisingly well. I recorded the notes for this post using the temporary Starlink connection as described, and completed the post with the "expedient" Starlink connection that is my sole Internet connectivity in N8GNJ Labs and my office.

Major elements of my Meadow Day "station:

• Starlink terminal - Starlink antenna (Dishy McFlatface), Starlink indoor unit (power supply / Wi-Fi access point), and the Starlink Ethernet adapter.
• Bluetti EB3A battery / power supply
• Generic 100 watt solar panel
• Cisco VOIP telephone (acquired as surplus)
• Macbook Air laptop with USB headset
• Table, chair, beverage, logging sheet

Similarities with Field Day:

• Simulate emergency conditions such as loss of power and other infrastructure.
• Communicate using only what you can carry or transport.
• Set up a communications facility (station) independent of existing communications infrastructure. While it's allowed in the Field Day rules to use an established Amateur Radio station, the intent is "get out into the field" to set up a temporary communications facility (which is what I chose to do for Meadow Day).
• Communicate "out of region" to bypass assumed loss of local communications infrastructure.
• Have fun doing so.

Differences with Field Day:

• I had no desire to accumulate contacts for "points" or other aspects of the overall contest structure of Field Day.
• I was only going to operate for a few hours.
• Field in my case was my house's yard, which is ~ 1 acre.
• Meadow Day was going to use technology of 2023 - Starlink, laptop, VOIP telephone, video conferencing, and a portable battery bank being charged with a solar panel.

Meadow Day 2023 Experiment - Photos

Basics of Meadow Day:

• Set up portable table and a camp chair
• Set up solar panel supplying power to portable battery bank
• Set up Starlink terminal in the yard (remote from the desk)
• Set up VOIP phone (connect to Ethernet adapter on Starlink)
• Set up laptop (connect to Starlink Wi-Fi)
• Connect to a number of friends using various videoconference systems (as the most demanding test of broadband capability).

N8GNJ Operating Position for Meadow Day 2023
Photo by Tina Stroh KD7WSF

N8GNJ Operating Position Desktop 1
Photo by Steve Stroh N8GNJ

N8GNJ Operating Position Desktop 2
Photo by Steve Stroh N8GNJ

Bluetti EB3A Display (poor visibility in direct sunlight)
Photo by Steve Stroh N8GNJ

Generic 100 Watt Solar Panel
Photo by Steve Stroh N8GNJ

The solar panel was casually positioned, leaning on a corner of the table. It was not optimized for angle or orientation, and it was a bit overcast. I have verified that in direct sunlight, it does generate the rated 100 watts (~12 Volts @ ~8.3 Amps). 

Bluetti EB3A Status via iPhone App (via Bluetooth)
Screenshot by Steve Stroh N8GNJ

Cisco VOIP Phone Configuring Itself
Photo by Steve Stroh N8GNJ

Funny story about this Cisco VOIP phone... I bought a small lot of these from someone six months to a year ago. I just grabbed this one out of the bin I had stored them in, and intended this to be just a "prop" for this story. For fun, because I had an Ethernet port available, I plugged it in. To my amazement, it connected to the host system (that this phone was removed from) and configured itself! I picked up the handset and got a "dialtone" (which was likely generated internally by the phone) and then dialed a couple of digits, and it worked. Not only were these phones not wiped of their configuration, but these phone's MAC addresses apparently weren't deleted from the host system. I'm sure that I could have dialed out with this phone, but I didn't want any accusation of "hacking" the host system. But it was obvious that VOIP works completely normally with Starlink.

Starlink Power Supply and Wi-Fi Access Point
Photo by Steve Stroh N8GNJ

Dishy McFlatface "deployed" (oriented Northwest)
Photo by Steve Stroh N8GNJ

This is the stand that each Dishy McFlatface (yes, that's the actual product name) is shipped with. It's intended as a starter as Starlink works best with an unobstructed view of the sky, which generally dictates a roof or tower mount. I was lucky that I have a large yard with few tall obstructions.

Approximate view of the sky of Dishy McFlatface. Note minor tree obstruction at bottom.
Photo by Steve Stroh N8GNJ

Starlink Status (1) via iPhone App (via Wi-Fi)
Screenshot by Steve Stroh N8GNJ

Note that the phone is in Airplane mode - Wi-Fi connectivity only.

Starlink Status 2 via iPhone App (via Wi-Fi)
Screenshot by Steve Stroh N8GNJ

For approximately the first 24 hours of operation, in a combination of downloading data from the Starlink satellites, trying different azimuth / elevation settings (Dishy has both attitude and rotational motors, though they're rarely used), and and observing outages with various satellites, Dishy will eventually orient itself to provide optimum connectivity. My Dishy orients itself to the Northwest where there are few obstructions.

Meadow Day 2023 Experiment - Contacts

One goal of Meadow Day was to utilize a number of different videoconference systems. Like almost all broadband Internet access systems (other than fiber), Starlink prioritizes downlink speeds over uplink speeds, so it was an interesting test to see if the various videoconference systems would work acceptably on Starlink, especially in this ad-hoc quick setup.

Prior to recording the following screenshot images, I verbally asked each participant for their permission to record a screenshot, and all agreed.

Contact 1 - Cale Mooth K4ACK via (Google Gmail) email

My first Meadow Day contact was to Cale Mooth K4ACK to try to set up a "contact", but he was busy and replied back to me later in the day. But his reply confirmed that there were no issues in using email via Starlink even with the quick setup.

Contacts 2 and 3 - Ken Koster N7IPB (left) and Bruce Miller KC7IAY (right) via Jitsi videoconference

Screenshot image recorded by Steve Stroh N8GNJ

Neither N7IPB or KC7IAY noted any issues with my video or audio quality.

Contact 4 - Merideth Stroh KK7BKI via Apple Facetime videoconference

Screenshot image recorded by Steve Stroh N8GNJ

KK7BKI didn't note any issues with my video or audio quality.

Contact 5 - Budd Churchward WB7FHC via Zoom videoconference

Screenshot image recorded by Steve Stroh N8GNJ

WB7FHC didn't note any issues with my video or audio quality.

WB7FHC recorded the video of our 26 minute conversation. We did a brief overview of what I was trying to accomplish with Meadow Day.

Video link My thanks to WB7FHC for editing our video conversation to a watchable 9 minutes.

Contact 6 - Steven Roberts N4RVE via Facebook Messenger videoconference

Screenshot image recorded by Steve Stroh N8GNJ

N4RVE didn't note any issues with my video or audio quality.

Contact 7 - Bill Vodall W7NWP via Signal videoconference

Screenshot image recorded by Steve Stroh N8GNJ

W7NWP didn't note any issues with my video or audio quality.

Contact 8 - Dewayne Hendricks WA8DZP via Signal videoconference

Screenshot image recorded by Steve Stroh N8GNJ

WA8DZP didn't note any issues with my video or audio quality.

Completed N8GNJ Meadow Day 2023 Logsheet.
Photo by Steve Stroh N8GNJ

Meadow Day 2023 Experiment - Conclusions

What was remarkable about my experience with Meadow Day 2023... was how unremarkable the experience was.

The Bluetti EB3A portable battery / inverter unit with the 100 watt solar panel just worked to provide AC power to operate the Starlink terminal and Cisco VOIP phone. I connected my laptop to the EB3A's USB-C port to charge it (that cost a bit of battery power). If the day had not been cloudy (direct sunlight) the solar panel would have provided a surplus of power.

When using Starlink as an emergency communications system, it's impressive just how plug and play Starlink is:

• Pull everything out of the box,
• A bit of minor mechanical assembly,
• Connect the cables,
• Place Dishy so that it can see the (as unobstructed as possible) sky (avoiding pointing at obstructions like trees will get online faster),
• Apply power to the router,
• Do a bit of configuration (name, password) in the phone app (only required for the initial setup),
• And… done! Online (via Wi-Fi) at broadband Internet speeds.

Within two minutes of powering up the Starlink, it was providing a broadband Internet connection. I cheated just a little bit knowing that in my area, Dishy McFlatface "prefers" to be facing Northwest, so I saved a bit of time by placing it in that orientation.

To be online at broadband speeds, capable of doing realtime video at reasonable quality, using no local infrastructure, required perhaps fifteen minutes of setup.

Could be better:

• The Bluetti EB3A, rated at 268 Wh (Watt Hours) was probably inadequate for extended operation (with no solar input) of the loads of:
  • Starlink terminal
  • VOIP phone (AC power adapter)
  • Laptop charging / operation
  • Small light (for nighttime operation)
  • Incidental charging - phone, etc.
• Newer, slightly more expensive solar panels are larger (provides more power), flexible, and lighter.

I deem "Meadow Day 2023" a success!

Notes:

(1) I didn't want there to be any confusion that my experiment had anything to do with Field Day, thus I created the title "Meadow Day".

(2) The Field Day event held during the Summer is ARRL Field Day. There is also Winter Field Day that is independent of ARRL.

Note - This post was actually completed and posted on 2023-10-16, but it will appear in the blog timeline as 2023-06-25, when I should have written and posted it.

Most new hams start with an HT (handie-talkie) radio. They’re very affordable, portable, and will get you on the air quickly. No one has to think about batteries and chargers—they’re almost always included. The only real decision is whether you want to buy a spare battery. 

Going mobile doesn’t take a lot of thought either. You find a place for the radio and remote head, then follow your car manufacturer’s recommendation for power connections. Technically the battery isn’t free, but you already have it.

However, when it comes to field operations like POTA, SOTA, and all the other OTAs, you should consider several factors before investing in a portable battery system. Things like weight, size, durability, and capacity become important considerations.

Understanding LiFePO4 & Other Portable Battery Types

Power for portable operations can come from various sources, like generators, solar, wind, and batteries (the primary choice of portable operators). Lithium-ion (Li-Ion), sealed lead acid (SLA), gel cell, and absorbent glass mat (AGM) are among those available.

However, the most efficient battery choice is a member of the lithium-ion family, LiFePO4 (lithium iron phosphate).

LiFePO4 is superior to other lithium-ion batteries for a couple of reasons. Number one is safety. The LiFePO4 chemistry has better thermal stability than lithium-ion. It will remain cool at room temperature while charging, while Li-Ion heats up faster and may potentially suffer from thermal runaway. LiFePo4 battery systems also contain built-in battery protection modules to address concerns like overvoltage and balancing. You probably remember stories about hoverboards whose lithium-ion battery packs began overheating, which led to sparking, catching fire, or melting.

The voltage supplied by a LiFePO4 is a good match for today’s radios.

Each fully charged cell produces 3.6V. With four cells in series (4S), a typical LiFePO4 battery pack comes in at 14.4V. The nominal voltage is 3.3V per cell, making the working voltage about 13.2V—an excellent choice for a typical 100W transceiver. 

Li-Ion/LiFePO4 batteries maintain a flat voltage curve compared to sealed lead acid or absorbent glass mat batteries, which start dropping voltage right from the beginning. SLA or AGM runtimes will be considerably shorter than a comparable Li-Ion or LiFePO4 battery.

Though people still buy lead-acid batteries because of their low prices, LiFePO4 is a better bargain in the long run. When you consider the lifespan of each type of battery, the LiFePO4 will last more than 12X longer, yet only costs 3-4 times the price. Lithium batteries will also hold a resting charge much longer—LiFePO4 is typically rated at 5% discharge per month.

Each one of these battery types has its pros and cons, and you can find in-depth discussions online about the nuances of each battery chemistry. However, what matters is which best suits your particular application and provides your gear with the appropriate voltage and operating time. If you’re looking for a simple and effective portable battery solution almost custom-designed to power radio gear, invest in a LiFePo4 battery and charger.

Which Battery Works Best for Ham Radio?

Everyone is looking for maximum operation time in the smallest package. SLA, gel cell, and AGM batteries will do the job but have drawbacks for portable operation, especially with weight and available power.

I suggest that those new to these battery packs look for something that is safe, hassle-free, and performs well. The battery management system built into the lithium batteries avoids the “oops” factor—it won’t let you draw more than their rated capacity.

For that reason, the lithium-ion battery—specifically a LiFePO4—is a no-brainer, especially the Bioenno Power line.

For example, Bioenno Power’s BLF-1220A LiFePO4 Battery is ideal for stationary applications requiring a higher capacity and greater power output.

The integrated PCM (Protection Circuit Module) provides complete internal cell balancing and management, protection from overcurrent, undervoltage (over-discharge), overvoltage, and short-circuiting, as well as integrated charging circuitry. As shown above, the BLF-1220A can also be purchased as a combo with a 14.6 VDC charger.

It’s easy to find various lithium-ion batteries online with a casual search. The problem is that you can quickly become overwhelmed by all the choices. I consulted with several hams who have experience with portable operation and got some excellent advice.

• QRP operation (10W or less, CW/SSB): A good starting point is a 6 Ah LiFePO4. It’s relatively small and will keep you going most of the day. If you intend to add digital, consider 10-12Ah instead.

• 100W operation: Sometimes you need an extra boost, especially in crowded bands or with marginal propagation. About a year ago, a friend suggested I purchase a 20 Ah LiFePO4 and use it during the Ohio State Parks on the Air event. It was used for at least five hours on sideband, with power to spare. I prefer a battery capacity that meets my needs so I don’t have to worry about recharging in the field.

When you buy, be sure you have the proper charger for LiFePO4 batteries. Some come in battery/charger combos like the above example. SLA chargers are NOT compatible and may damage a LiFePO4 battery. Whatever you do, don’t compromise on your battery and charging system.

Useful Info

The following will help you get a better understanding of your battery needs and help you narrow the options.

How Much Power Am I Really Using? Weighted Average Calculation

Your radio doesn’t demand a consistent amount of power; rather, it varies according to the transmit time, receive, and transmit modes used. According to the Yaesu FT-891 mobile transceiver manual, the receive takes about 2W while the transmit may take as much as 23W. Sideband will draw less power than a continuous mode like FT-8 or RTTY.

Weighted averages will give you a better picture of power consumption.

Weighted Average Formula:

(x) * (power ₁) + (1-x) (power ₂)

Example

20% of time transmit at 100W

80% of time receive at 2W

0.20*100 + 0.82*2= 21.6 

11 hours of run time on 20 Ah LiFeP04 ([12v x 20 Ah]/21.6)

Don’t forget to account for accessories such as portable tuners.

Live Testing

Inline DC Power Analyzers and wattmeters allow you to measure and monitor the DC power consumption of your portable equipment. These DC power meters read voltage, current, watts, amp/hours, and watt/hours. They’re connected between the power supply and radio to help you monitor power consumption. 

You can also utilize these as part of your portable OTA gear, which gives you real-time information about your battery’s state while operating.

E-Z Match

Bioenno mobile transceiver compatibility guides cover the most popular radios. They are available on the DX Engineering website at the links below.

• Elecraft, Kenwood, Flex Radio
• Yaesu, Icom

In addition, Bioenno provides battery runtime charts for all their models

• Bioenno duty cycle guide 20/80 – normal
• Bioenno duty cycle guide 50/50 – contesting/Field Day

The post Ham Radio Tech: Choosing a Battery System for Portable Operations appeared first on OnAllBands.

Its another gig sitting my “Grand Kittens” for my daughter as she and her hubby will be out of town from September 20th for a week. I guess I did a good job when they went to Cuba last January so I got invited back… I will be operating /p from Ottawa from September 21st to September 27th.

Most of my operating will be from September 23rd onwards.

As you can see from the above pic… they like having me around (one cat at least)

This time its a bit different because the car will be going with them to their rental cottage which is about 2 hours north of Ottawa.

However I plan to take both my Portable Station and my Transportable Station with me so I can activate some POTA locations with the Xiegu X5105 and also use my Yaesu FT 891 as I control the Trans Provincial Net for my 11am slot.

Before we go any further please remember that all my RF Plans you will see below are if the weather is good. I don’t like operating outside in the rain and neither do my radios….

The closest park to where they live is a City Park and not a POTA park.

The park has two sport fields and they have bleachers so it will be easy as I will have somewhere to sit along with strap my MFJ 33 foot mast to so the EFHW will have some altitude.

That will allow me to act as NCS with a 100w station with a full size antenna.

Once the net is over I will be packing up and heading back to the apartment for lunch. In the afternoons…. Once again if the weather is cooperating I plan to take the X5105 out to one or two of the local POTA Parks for a couple of hours. Check POTA Spots….

Due to the fact of not having access to a vehicle I will be heading out either on foot or public transport. After checking the POTA map it seems there are quite a few POTA sites that are fairly easy to access via the Bus and LRT service. However a few of the “Locals” have mentioned that they might pick me up and we could do an activation as a group so you never know.

They say that “getting there is half the fun” and this might be the case.

Stay tuned…

73bob

Yes its an old picture but the hobby has been fun since the 1990’s

Its another gig sitting my “Grand Kittens” for my daughter as she and her hubby will be out of town from September 20th for a week. I guess I did a good job when they went to Cuba last January so I got invited back… I will be operating /p from Ottawa from September 21st to September 27th.

Most of my operating will be from September 23rd onwards.

As you can see from the above pic… they like having me around (one cat at least)

This time its a bit different because the car will be going with them to their rental cottage which is about 2 hours north of Ottawa.

However I plan to take both my Portable Station and my Transportable Station with me so I can activate some POTA locations with the Xiegu X5105 and also use my Yaesu FT 891 as I control the Trans Provincial Net for my 11am slot.

Before we go any further please remember that all my RF Plans you will see below are if the weather is good. I don’t like operating outside in the rain and neither do my radios….

The closest park to where they live is a City Park and not a POTA park.

The park has two sport fields and they have bleachers so it will be easy as I will have somewhere to sit along with strap my MFJ 33 foot mast to so the EFHW will have some altitude.

That will allow me to act as NCS with a 100w station with a full size antenna.

Once the net is over I will be packing up and heading back to the apartment for lunch. In the afternoons…. Once again if the weather is cooperating I plan to take the X5105 out to one or two of the local POTA Parks for a couple of hours. Check POTA Spots….

Due to the fact of not having access to a vehicle I will be heading out either on foot or public transport. After checking the POTA map it seems there are quite a few POTA sites that are fairly easy to access via the Bus and LRT service. However a few of the “Locals” have mentioned that they might pick me up and we could do an activation as a group so you never know.

They say that “getting there is half the fun” and this might be the case.

Stay tuned…

73bob

Yes its an old picture but the hobby has been fun since the 1990’s

Life is great IF you can get everything happening when it should. Today was living of proof of having to improvise and adapt….

Liz (the patient one who tolerates/supports this hobby) had a follow up appointment at the Providence Care Health Facility here in Kingston for 1030 am… At 11am I was supposed to be the Net Control Station for the Trans Provincial Net on 7.100.

This is a conflict and I have to give priority to Liz…. But here was the solution and it worked…

I dropped her off at her appointment for 10:15 and then walked out the back door of the Health Facility and into POTA CA-6003 which is the Great Lakes Waterfront Trail.

In the above graphic the Health Care Facility if the Grey building and the Trail is the thin green line right below it.

I had activated from there before and knew which trees would work with what picnic tables.

And yes I had brought my “Transportable Station” with me….

The FT891 was quickly hooked up to the 20AH battery and my “HomeBrewed” EFHW was strung between the trees… I managed to make a couple of POTA Contacts on 40m before the TPN started up at 11am. (thanks for the 2fer Bill) I managed to wrangle up 9 Checkins to the net which is not too bad as I took the summer off from my regular 11 am shift.

After the net ended I managed a couple of POTA contacts on 20m SSB which made it a successful POTA activation along with keeping up with my obligations to the Net. At 12:15 Liz sent me a text telling me she was finished and to meet her in the coffee shop in the facility. At 12:30 I met her in the coffee shop and we headed back home.

All in all it was a busy but fun start to the day…

73bob

Life is great IF you can get everything happening when it should. Today was living of proof of having to improvise and adapt….

Liz (the patient one who tolerates/supports this hobby) had a follow up appointment at the Providence Care Health Facility here in Kingston for 1030 am… At 11am I was supposed to be the Net Control Station for the Trans Provincial Net on 7.100.

This is a conflict and I have to give priority to Liz…. But here was the solution and it worked…

I dropped her off at her appointment for 10:15 and then walked out the back door of the Health Facility and into POTA CA-6003 which is the Great Lakes Waterfront Trail.

In the above graphic the Health Care Facility if the Grey building and the Trail is the thin green line right below it.

I had activated from there before and knew which trees would work with what picnic tables.

And yes I had brought my “Transportable Station” with me….

The FT891 was quickly hooked up to the 20AH battery and my “HomeBrewed” EFHW was strung between the trees… I managed to make a couple of POTA Contacts on 40m before the TPN started up at 11am. (thanks for the 2fer Bill) I managed to wrangle up 9 Checkins to the net which is not too bad as I took the summer off from my regular 11 am shift.

After the net ended I managed a couple of POTA contacts on 20m SSB which made it a successful POTA activation along with keeping up with my obligations to the Net. At 12:15 Liz sent me a text telling me she was finished and to meet her in the coffee shop in the facility. At 12:30 I met her in the coffee shop and we headed back home.

All in all it was a busy but fun start to the day…

73bob

Figure 1: Power/VSWR meter using ИН-13 (a.k.a. "IN-13") neon bar-graph indicators. Click on the image for a larger version.

Several years ago I bought some Soviet-era neon bar-graph displays - mainly because I thought that they looked cool, but I didn't have any ideas for a specific project.  

Figure 2: A pair of ИН-13 neon indicator tubes.  These tubes are slightly longer than than the ИН-9 tubes and have three leads Click on the image for a larger version.

For a device that is intended to indicate specific measurements, it's important that it is consistent, and for these neon indicators, that means that we want the bar graph to "deflect" the same amount anytime the same amount of current is applied to it.  In perusing the specifications of both the  ИН-9 and  ИН-13 it appeared that the  ИН-13 would be more suitable for our purposes.

Figure 3: Test circuit to determine the suitability of various inductors and transistors and to determine reasonable drive frequencies.  Diode "D" is a high-speed, high-voltage diode, "R" can be two 10k 1 watt resistors in parallel and "Q" is a power FET with suitably high voltage ratings (>=200 Volts) and a gate turn-on threshold in the 2-3 volt range so that it is suitable to be driven by 5 volt logic.  V+ is from a DC power supply that is variable from at least 5 volts to 10 volts.  The square wave drive, from a function generator, was set to output a 0-5 volt waveform to make certain that the chosen FET could be properly driven by a 5 volt logic-level signal from the PIC as evidenced by it not getting perceptibly warm during operation.

Generating high voltage from a low is one of the aspects that I tackled in a previous project on this blog when I built a high voltage power supply for the Zenith Transoceanic:  You can read about that here - A microcontroller-based A/B Battery replacement for the Zenith TransOceanic H-500 radio, with filament regulation - link.

Figure 4: The voltage boost converter section showing the transistor/inductor, rectification/filtering and voltage divider circuitry.

Description:

 

Figure 5: The precision current sinks that drive the neon tubes precisely based on PWM-derived voltage. Click on the image for a larger version.

Figure 6: An exterior view of the tandem coupler module. Visible is the top shield and the three feedthrough capacitors used to pass voltage and block RF. Click on the image for a larger version.

RF sensing

For sensing forward and reflected power I decided to use an external "sensing head" that was connected inline with the radio, on the "tuner" side of the feedline.  

For sensing power in both directions I chose the so-called "Tandem" coupler which consists of a through-line sampler in which a short length of coaxial cable carrying the transmit power (T1 in the diagram of Figure 7) passes through a toroidal core - using some of the original cable's braid grounded at just one end as a Faraday shield.  An identical transformer (T2) is connected across the first (T1) for symmetry.

When carefully constructed this arrangement has quite good intrinsic directivity and a wide frequency range.  Figure 6 shows the diagram of this section.

Figure 7: Schematic diagram of the "Tadem" coupler.  A bidirectional coupler sends power to separate AD8307 logarithmic amplifiers - one for forward and the other for reverse. The outputs, expressed in "volts/dB" are sent to the microcontroller. Click on the image for a larger version.

The RF sensing outputs of the second tandem coupler (T2) then goes through resistive voltage dividers (R606/R607 for the reverse sample and R603/604 for the forward sample) to a pair of Analog Devices AD8307 logarithmic amplifiers - one for forward power and the other for reverse - to provide a DC voltage that is logarithmically proportional to the detected RF power.  This voltage is then coupled through series resistors (for both RF and DC protection) R605/R608 and to the outside world using feedthrough capacitors.

The use of a logarithmic amplifier precludes the need to have range switching on power meter as RF energy from well below a watt to well over 2000 watts can be represented with only a few volts swing.  Looking carefully at Figure 6 one can see a label that notes that the response of the AD8307 is about 25 millivolts per dB - and this applies across the entire power range of a few hundred milliwatts to 2000 watts.

All of this circuitry is mounted in a box constructed of circuit board material and connected to the display unit with an umbilical cable that conveys power and ground along with the voltages that indicates forward and reflected power.

Figure 8: An inside view of the Tandem Match (sense unit) showing the coupling lines, internal shielding and AD8307 boards. Click on the image for a larger version.

The AD8307 detectors themselves can be seen at the left and right edges of the lower half of the unit, built on small pieces of perfboard.  All signals - including the 12 volt power and the DC voltages of the output pass through 4000pF feedthrough capacitors to prevent both ingress and egress of RF energy which could find its way into the '8307 detectors and skew readings.

* * * * *

In a future posting (Part 2) we'll talk about the final design and integration of this project.

This page stolen from ka7oei.blogspot.com

[END]

Remember yesterday when I mentioned the latest addition to my POTA setup, the Xiegu 5105 QRP rig….

Well this morning I decided to test it out and see how much work I would have to do with setting the parameters such as mic gain, processor, to make it sound like me… I was also testing out my EARCHI 9:1 unun with a 29.5 foot random wire to see how it would play with the built in AT of the 5105.

I figured I might as well do the testing at a POTA location just in case I was able to turn the test into an activation.

For this I chose Fort Frontenac POTA CA-5303. Its fairly easy to get there via the Kingston Transit system and its also close to downtown and all the amenities I might need. In the North East corner of the picture you will notice some white lines on the ground.

They are actually the walls of what’s left of that part of the Fort. Also the only parts of the Historic Site that is open to the public.

I leaned my MFJ 33 foot mast (supporting the 9:1 and wire in the vertical configuration) up against the tree.

And then ran the COAX over to the remains of the wall and set up my radio there and started operating.

My first contact was on 7.255 with the NCS of the ECARS net. He did hear me and considering I was QRP I was pleased. He did tell me that my audio seemed hot as if I was overdriving things. Lowering my voice seemed to help.

After that I looked at POTA Spots and managed to get W2IDG and VE3FI into the log from their parks and then finished up with the NCS of the MidCars net on 7.258.. All contacts were made on 40m SSB. I tried 20 SSB and was hearing lots of stations including a POTA Activation in VO1 but no luck breaking any of the pileups.

Then I figured it was time to get home and try to re configure the radio to my liking… I turned off the Speech Processor and lowered the Mic Gain from 60 to 40. Over the next few days I will get out again and see what else I have to do to get things sounding right.

Till then

73bob