Well its not as bad as indicated from my last post…

But its still got a way to go…

This morning on my 11 am (Eastern) hour on the TPN I managed to get 7 stations in my log which is the best its been in a while. After the net ended I had some household chores to do before I could get to the next part of this post.

Today I wanted to take my Yaesu FT891 rig along with my two antennas out into my backyard and make sure everything is still working as well as I remember. Next week my shifts on the TPN will be ending for a while as I am taking the summer off in an attempt to concentrate on my POTA part of the hobby.

So here’s the setup

Rig: Yaesu FT891 powered by my ECO-Worthy 20ah LI-PO4 battery

Antenna 1: 40m EFHW which is 63 feet long and fed by a 64:1 unun. This antenna usually is used in a sloper or inverted Vee configuration. Its very nice on 10-40m and I have 2 small counterpoises which I clip on as needed. I feed the unun from a 25 foot run of RG58 with a RF choke at one end.

Antenna 2: 17.5 foot long end fed fed by a 9:1 unun. I normally would use this in a vertical or sloper configuration. Its excellent on 10m to 20m but will also work on 40m without the need of a tuner. Depending on the situation I have a couple of small counterpoises I can clip onto the unn if needed. I feed the unun from a 25 foot run of RG58 with a RF choke at one end. The advantage to this antenna is that if I use it as a vertical there is next to no footprint which could make a couple of the parks in the downtown area much easier to activate.

If the trees do not cooperate I also carry a MFJ 33 foot telescopic masting which will support the wire if needed.

How did I do today?

Operating from my deck I strung out the 63 foot EFHW kind of as an inverted xyz configuration. Hanging 63 feet of wire anywhere I could hand it without anyone seeing it or running into it. Despite the setup Contacts were made on 40m and 20m despite the band conditions. with a reasonable SWR (no tuner in line) where I normally use it

Next I used the 17.5 with the 9:1 unun as a low sloper and made 1 contact on 20. The SWR was “tolerable” on 40m but on 10m to 20m it was under 2:1 which is great for a Portable setup. Nothing to complain about on my part.

I also use this style of antenna at home in a vertical configuration and it works great for my need either “home or away”

So here’s the plan…

If you notice the above map there are 10 POTA sites (yellow dots) that I can easily access from my home in Kingston. All of them easily reachable via public transit or a bit of a walk. The one on the bottom right (the island) is not reachable via foot. There is a dock but I can’t find out if Kingston has a Water Taxi so if I can activate 10 out of 11 I will be pleased.

I guess I could also say that this would be a test of the station I will be using for Field Day this year. Not sure where I’m going to be yet but…. I know I’ll be participating from somewhere near Kingston.

.

Till next time

73bob

Well its not as bad as indicated from my last post…

But its still got a way to go…

This morning on my 11 am (Eastern) hour on the TPN I managed to get 7 stations in my log which is the best its been in a while. After the net ended I had some household chores to do before I could get to the next part of this post.

Today I wanted to take my Yaesu FT891 rig along with my two antennas out into my backyard and make sure everything is still working as well as I remember. Next week my shifts on the TPN will be ending for a while as I am taking the summer off in an attempt to concentrate on my POTA part of the hobby.

So here’s the setup

Rig: Yaesu FT891 powered by my ECO-Worthy 20ah LI-PO4 battery

Antenna 1: 40m EFHW which is 63 feet long and fed by a 64:1 unun. This antenna usually is used in a sloper or inverted Vee configuration. Its very nice on 10-40m and I have 2 small counterpoises which I clip on as needed. I feed the unun from a 25 foot run of RG58 with a RF choke at one end.

Antenna 2: 17.5 foot long end fed fed by a 9:1 unun. I normally would use this in a vertical or sloper configuration. Its excellent on 10m to 20m but will also work on 40m without the need of a tuner. Depending on the situation I have a couple of small counterpoises I can clip onto the unn if needed. I feed the unun from a 25 foot run of RG58 with a RF choke at one end. The advantage to this antenna is that if I use it as a vertical there is next to no footprint which could make a couple of the parks in the downtown area much easier to activate.

If the trees do not cooperate I also carry a MFJ 33 foot telescopic masting which will support the wire if needed.

How did I do today?

Operating from my deck I strung out the 63 foot EFHW kind of as an inverted xyz configuration. Hanging 63 feet of wire anywhere I could hand it without anyone seeing it or running into it. Despite the setup Contacts were made on 40m and 20m despite the band conditions. with a reasonable SWR (no tuner in line) where I normally use it

Next I used the 17.5 with the 9:1 unun as a low sloper and made 1 contact on 20. The SWR was “tolerable” on 40m but on 10m to 20m it was under 2:1 which is great for a Portable setup. Nothing to complain about on my part.

I also use this style of antenna at home in a vertical configuration and it works great for my need either “home or away”

So here’s the plan…

If you notice the above map there are 10 POTA sites (yellow dots) that I can easily access from my home in Kingston. All of them easily reachable via public transit or a bit of a walk. The one on the bottom right (the island) is not reachable via foot. There is a dock but I can’t find out if Kingston has a Water Taxi so if I can activate 10 out of 11 I will be pleased.

I guess I could also say that this would be a test of the station I will be using for Field Day this year. Not sure where I’m going to be yet but…. I know I’ll be participating from somewhere near Kingston.

.

Till next time

73bob

If you were checking the Trans Provincial Net Website you might of noticed a small blurb mentioning I will be taking the summer off.

“Bob VA3QV will be away starting 18th May till  September 2024.”

I currently cover the 11am (EST) hour 5 days a week and I do enjoy being a NCS…. But… Now that the nicer weather is finally looking like it might arrive… I decided I would prefer to spend it doing other stuff compared to sitting in the shack for a while.

No doubt that radio will be a big part of my summer but it won’t be from the shack unless its raining.

As always if I am doing (or have done) anything interesting in radio you will be able to read about it right here.

73bob

If you look back to my previous post in which I had covered my successful POTA activation of CA5143 I mentioned that I had used my 40m EFHW antenna to make the 23 contacts made.

Well one thing I neglected to mention was the difficulty I had getting 62 feet (or so) wire stretched out in the rather dense brush just off the trail. In the past I had mentioned about getting a 2nd antenna in the kit for when the EFHW was just not able to be deployed easily.

I had tried a BuddiPole but it did not (could not) do exactly what I wanted…. Using some parts from the BuddiPole and then adding a “Imitation” Shock Corded 9 foot whip (In my opinion…FWIW the Amazoon 9.5 ft shock cord whip is a real POS)was not doing it for me either. I tried following the instructions and when those did not work I tried (to no avail) to use what I tried in the past with other portable antennas but just no joy…

Fast forward to yesterday. The LDG 9:1 UNUN that I ordered on the Monday had arrived and so I decided to duplicate the “Coastal-20” antenna that I use at home for 10-12-15-17 & 20m. If you “Google Coastal-20 you should see the basic plans. Its a 9:1 UNUN along with a 17.5 foot vertical with a short counterpoise.

Now on my first build I found the short counterpoise version did not perform exactly as I had hoped so I decided to go with 3 elevated counterpoises. I cut 1 for 10-15 &20m and it worked quite well for me on 10 to 20m. By well I mean that I was making contacts and the SWR on all the needed bands was low or low enough that the internal tuner in my Yaesu FT991a was handling it.

Mostly copying my first version with the exception of swapping out 3 counterpoises for a single 11 foot counterpoise seemed to make no difference with the SWR and it was loading up just as well as the previous one did.

The next test for the new antenna will be when I get out into the Park (hopefully this weekend) if the forecasted rain ever stops. The plan is to have both antennas available for when I participate in the POTA Support your Parks event which happens April 20th and 21st and by strange luck is also the same weekend as the Ontario QSO Party, The Michigan QSO Party and the Quebec QSO Party so there should be no problems getting contacts to activate what ever park (parks) I head out to…

73bob

This antenna modelling session came about after a conversation with Michael, DK1MI on the Matrix. I believe the antenna design was originally done by Artur, M0PLK with reviews being on EHAM.

The antenna takes the form of a simple inverted triangular loop with a 5.8m flat top and two diagonals each 5.6m long coming down to a point. The antenna is fed in the centre of the flat top with 450 Ohm open ladder line and a 4:1 Balun. This antenna will require an ATU on all bands as the modelling shows a very wide range of impedances at the feed point.

The design seems to suggest using two fixed aluminium tubes with the wire fed up through them for the two diagonal elements of the antenna however, it would probably be easier to use a pair of collapsable fibre glass poles (Not Carbon fibre) with the wire attached via some clips or tape.

I decided to model the antenna with the top horizontal wire 10m above ground putting the point of the triangle 5.2m above ground. I felt this was an achievable height for most HAMs. Lowering the antenna will raise the resultant angle of maximum radiation on all bands.

Looking at the 2D Far Field Plots (2DFFP) the antenna radiates through the loop as expected with a higher radiation angle on the lowest band and the lowest radiation angle on the highest band. The antenna is of course bi-directional and so could be rotated just 180 degrees to obtain global coverage.

On the 30m band the antenna has a very high angle of maximum radiation making it ideal for short distances. There is a little gain to be had at 25 degrees however, this is nowhere near the maximum but, will possibly aid working longer distances. A maximum gain of 5.31dBi is obtained at 72 Degrees on the 30m band.

On the 20m band the 2DFFP is fairly similar to that of the 30m band but, with 5.57dBi gain at a lower angle of 34 Degrees. This will provide excellent results on medium distance contacts and reasonable results on the long haul.

Once above 14Mhz things start to get more interesting. From the 17m band upwards the radiation pattern changes quite drastically and starts to provide some excellent gain at relatively low angles. This will improve the antenna’s DX performance considerably on the higher bands.

Looking at the 17m band the angle of maximum radiation is now down to 26 degrees with a gain of 7.64dBi. At 12 degrees there is a gain of 4.59dBi. This radiation pattern will make this antenna ideal for the medium to long haul contact with very little interference from NVIS signals.

The 15m band follows the trend with the angle of max radiation now down to 22 degrees with a max gain of 8.54dBi. Even at 10 degrees there is a gain of 5.34dBi which will be very welcome for DXing. There is slightly more near vertical incident skywave (NVIS) radiation on the 15m band and so the antenna should provide short, medium and long haul contacts with the latter being favoured.

Moving up to the 12m band the angle of maximum radiation now comes down to 18 degrees with a gain of 8.61dBi. There is also 5dBi of gain to be had at 8 degrees which is ideal for DXing. Unfortunately there is slightly more NVIS radiation on the 12m band than there is on the 15m band. I’m sure with a little change in height this could be reduced such that the antenna provides only low angle radiation.

Finally we reach the 10m band, this is where the antenna has the lowest angle of maximum radiation. With 8.56dBi gain at 16 Degrees, 5.59dBi at 8 degrees and a much reduced NVIS radiation. This antenna should be excellent for the long haul on 28-29Mhz. (It would also make an excellent 11m/CB antenna).

It’s interesting to note the similarities between this multi-band delta loop design and my Bi-Directional Slot Fed Antenna design. They both exhibit very similar radiation patterns and gain figures with the Slot Fed Antenna providing slightly more gain and an even lower angle of maximum radiation on the supported bands.

Overall this easy to construct multi-band delta loop antenna would be ideal for the HAM that just wants a single antenna for 30m and upwards or is looking to go portable. The only disadvantage is that a good Remote Auto ATU is required to provide matching of the antenna to the 50 ohm coax at the feed point. Something like the LDG RT100 would be an ideal ATU choice for this application and would remove the losses caused by having a high SWR on the coax feed to the antenna.

Using an ATU in the radio in the shack isn’t going to provide the same results as the coax cable from the antenna to the shack will become part of the antenna and will be detrimental to the antenna performance. It will also create high losses on the coax feed to the antenna due to high SWR being present over the length of the coaxial feed.

I’ve had this antenna model for ages now but, never got round to putting it onto the website until Alex, GM5ALX was talking about making one the other day whilst chatting on the QO-100 satellite.

The 20m band delta loop follows exactly the same design principles as all the other delta loop designs I’ve already put on the website. They are designed such that they present a 50 ohm impedance at the feed point and thus have no requirement for complex impedance matching circuits/transformers.

The dimensions for the antenna are as follows:

Wire 1 – Horizontal exactly 1m above the ground for its entire 10.2m length.
Wires 2 & 3 are exactly 6.18m long each with the top being 4.5m above the ground.

The 3D far field plot shows a typical delta loop radiation pattern with the maximum radiation through the loop and a deep null in the centre.

The 2D elevation plot shows that the antenna will give a maximum gain of -0.79dBi at 30 degrees when used over average/poor soil types. If like me you use your Delta Loop antennas on the beach then the antenna will present considerably more gain as it will benefit from the salt water reflection.

If you want to lower the angle of maximum radiation and increase the gain over average ground just raise the antenna up so that the top is around 7m above ground. This will give a much lower angle of radiation and improve the gain figure by 2-3dBi. Don’t forget that if you raise the antenna the point of resonance will also rise in frequency and so you may need to shorten the wires a little to get the point of resonance back to where you want it.

The SWR plot shows that the antenna will have a fairly wide bandwidth and match to 50 ohm coax extremely well. The antenna is designed to be fed in one of the lower corners via a 1:1 balun for best results.

Summary:

Total Wire Length: 16.38m
Horizontal Wire Length: 10.2m @ 1m above ground
Diagonal Wire Lengths: 6.18m
Wire Dia: 2.5mm
Height at Centre: 4.5m
Feed Type: 1:1 Balun in bottom corner (Can use coax if necessary)
Impedance: 50 Ohm
SWR: <1.5:1 at resonance

Since setting up the new HAM station here in the UK the one band I’ve not yet got back onto is 160m, one of my most favourite bands in the HF spectrum and one that I was addicted to when I live in France (F5VKM).

Having such a small garden here in the UK there is no way I can get any type of guyed vertical for 160m erected and so I needed to come up with some sort of compromise antenna for the band.

Only being interested in the FT4/8 and CW sections of the 160m band I calculated that I could get an inverted-L antenna up that would be reasonably close to resonant. It would require some additional inductance to get the electrical length required and some impedance matching to provide a 50 Ohm impedance to the transceiver.

Measuring the garden I found I could get a 28m horizontal section in place and a 10m vertical section using one of my 10m spiderpoles. This would give me a total of 38m of wire that would get me fairly close to the quarter wave length.

For impedance matching I decided to make a Pi-Network ATU. I’ve made these in the past and found them to be excellent at matching a very wide range of impedances to 50 Ohm.

Since I still had the components of the Pi-Network ATU that I built when I lived in France I decided to reuse them as it saved a lot of work. The inductor was made from some copper tubing I had left over after doing all the plumbing in the house in France and so it got repurposed and formed into a very large inductor. The 2 x capacitors I also built many years ago and fortunately I’d kept locked away as they are very expensive to purchase today and a lot of work to make.

Getting the Inverted-L antenna up was easy enough and I soon had it connected to the Pi-Network ATU. I ran a few radials out around the garden to give it something to tune against and wound a 1:1 choke balun at the end of the coax run to stop any common mode currents that may have appeared on the coax braid.

Connecting my JNCRadio VNA I found that the Inverted-L was naturally resonant at 2.53Mhz, not too far off the 1.84Mhz that I needed. Adding a little extra inductance and capacitance via the ATU I soon had the antenna resonant where I wanted it at the bottom of the 160m band.

With the SWR being <1.5:1 across the CW and FT8 section of the band I was ready to get on 160m for the first time in a long.

Since it’s still summer in the UK I wasn’t expecting to find the band in very good shape but, was pleasantly surprised. Switching the radio on before full sunset I was hearing stations all around Europe with ease. In no time at all I was working stations and getting good reports using just 22w of FT8. FT8 is such a good mode for testing new antennas.

As the sky got darker the distance achieved got greater and over time I was able to work into Russia with the longest distance recorded being 2445 Miles, R9LE in Tyumen Asiatic Russia.

In no time at all I’d worked 32 stations taking my total 160m QSOs from 16 to 48. I can’t wait for the long, dark winter nights to see how well this antenna really performs.

The map above shows the locations of the stations worked on the first evening using the 160m Inverted-L antenna. As the year moves on and we slowly progress into winter it will be fun to start chasing the DX again on the 160m band..

UPDATE 6th October 2023.
Been using the antenna for some time now with over 100 contacts on 160m. Best 160m DX so far is RV0AR in Sosnovoborsk Asiatic Russia, 3453 Miles using just 22w. Pretty impressive for such a low antenna on Top Band.

More soon …

This is a 15m band delta loop design that I’ve put together as requested by Wim, PE1PME.

The 15m band delta loop follows exactly the same design principles as all the other delta loop designs I’ve already put on the website. They are designed such that they present a 50 ohm impedance at the feed point and thus have no requirement for complex impedance matching circuits/transformers.

The dimensions for the antenna are as follows:

Wire 1 – Horizontal exactly 1m above the ground for its entire 7m length.
Wires 2 & 3 are exactly 4.12m long each with the top being 3.18m above the ground.

The 3D far field plot shows a typical delta loop radiation pattern with the maximum radiation through the loop and a deep null in the centre.

The 2D elevation plot shows that the antenna will give a maximum gain of 1.5dBi at 26 degrees with useful gain at lower angles.

The SWR plot shows that the antenna will have a fairly wide bandwidth and match to 50 ohm coax extremely well. The antenna is designed to be fed in one of the lower corners via a 1:1 balun for best results.

Summary:

Total Wire Length: 15.24m
Horizontal Wire Length: 7m @ 1m above ground
Diagonal Wire Lengths: 4.12m
Wire Dia: 2.5mm
Height at Centre: 3.18m
Feed Type: 1:1 Balun in bottom corner (Can use coax if necessary)
Impedance: 50 Ohm
SWR: <1.5:1 at resonance

 Well,

Lots of discussions about my baluns and the test setup, a common question seems to be how to measure the output impedance.

Here's my way:

Fun, dont you think?