In 1957 I had two important subjects firmly on my mind: Girls and Only 2 more years before I could escape my boring town in Western Pennsylvania -- about 30 Miles from Butler, PA which of course is in the news today.
That is my excuse for not spotting this jewel when it was first published in 1957.
Wow! A 200 milli-watt CW transmitter, all solid-state using RCA Transistors. With some attention to biasing you likely could pop in the circuit, transistors like the 2N3906, 2N2907, 2N4403 or a 2N2905. The Oscillator is a Common Base, and the Amp is a Common Emitter.
[Check Google as to why the Common Base for the Oscillator like Voltage Gain, Input Impedance, Stability, Biasing etc.]
Speaking of Biasing note the use of multiple batteries versus resistance biasing. The Oscillator is keyed, and the Oscillator/Amp is switched on during transmit using SW1. By switching on SW2 a lesser collector voltage is applied likely a spotting signal.
There are three meters in the rig and the output circuit and antenna tuner should provide for good harmonic suppression. Note also JIC (just in case), the output has a wavemeter coupled to the output to assure you are transmitting with "max smoke" on the right band. BTW 200 milliwatts of RF at 7MHz was a big deal in 1957!
I will bet the signal quality, in large, depended on the crystals being used. The plated type might yield a whoop, whoop sound as you keyed the rig. A good place for the FT-243 type.
You can find the complete article by searching for N4TRB + RCA Ham Tips ~ July 1957. This schematic has great potential for a 2024 makeover with less parts, less cost and more power output.Β
Again, the fun of looking at something from 67 years ago and remaking it with modern components. There is also another incentive to not directly replicate this design -- the cost. The eBay auction site currently has an RCA 2N140 transistor for about $20 shipped.
This is a really wonderful video.Β I especially liked his presentation on the nature of the EM spectrum, and his use of the centimeter waves to demonstrate wave behaviour.Β Β The two slit experiment was very nice.Β Β Sir Lawrence's presentation on SWR was brilliant.Β Β
Still, you wonder how would all this be done if those waves of Sir Lawrence (and Young, Maxwell and Faraday) were considered to be the photons that they also really are?Β
Many thanks to SWLing Post contributor, Bob Purse, owner and curator of the excellentΒ Inches Per Second audio archive and blog, who recently posted a 1968 recording of Radio Australia. This recording is in the queue to be published on the Shortwave Radio Audio Archive, but I thought Iβd share it here first since I know [β¦]
Many thanks toΒ SWLing PostΒ contributor and noted political cartoonist,Β Carlos Latuff, who sharesΒ his radio log art and recording from RΓ‘dio Mitre: Carlos notes: ββ¦World commotion, Donald Trump assassination attempt. It was at a campaign event in Pennsylvania. While the Republican candidate was giving his speech, several shots were heard and immediately afterwards he fell with a wound [β¦]
Iβve had a lot of fun with my Elecraft AX1 antenna since I bought it six or seven years ago. Iβve activated several parks with it, and it has yet to let me down. Running five watts into a 45-inch whip shouldnβt really work, but somehow it does. While I donβt always use it as my primary antenna, I always take it along on outings as a backup.Β
I have used my AX1 in a variety of settings, e.g., picnic table portable, with a car window mount, clamped to the handlebars of my bike, etc. While perusing the Temu website, I stumbled upon a tactical-style MOLLE pouch capable of holding the AX1 and all the accessories I typically use for those configurations. The cost was a mere $8.00 (USD) for a pair of them.Β (The original offering is no longer available, but a search for βmolle pouchβ on Temu or AliExpress should find this pouch or something similar.)
AX1 Kit (front). I have two of these pouches, so I used a nylon zip tie label to tell them apart. AX1 Kit (Rear). The pouch is MOLLE-compatible.
It measures 6.3 in. (16cm) x 4.33 in. (11cm) x 2.1 in. (5.5cm). For as inexpensive as they are, the quality is pretty good. The material is durable, and the zipper works smoothly. Each pouch came with an American flag velcro patch.Β At these low prices, you often get what you pay for. This time, though, I think it was a pretty good deal.
Everything fits comfortably in the little pouch, but there isnβt much room to spare.Β
This is what I carry in my AX1 kit. Not shown is a 3-foot RG-316 coax cable. (See text for list)
I normally carry my AX1 pouch in my backpack. When I have too much other stuff in my pack, I can use the MOLLE straps to attach the pouch to the outside of the pack.Β
Itβs nice having all of this stuff in one place. Now my little AX1 is always ready to go, however I plan to use it.
Usually, the Es season in Europe goes "off the boil" about now. Es can occur at any time of the year, although the peak times are in spring and early summer.
It is interesting that most of my spots on 10m QRP FT8 this morning were probably F2.
This morning, we see on the news that Donald Trump narrowly missed an attempt on his life.
The USA has a gun culture and a very high death rate due to guns. It is sad that political candidates cannot give their "pitch" without the fear of being shot.
At 0808z my 2.5W 10m FT8 had been spotted by 33 stations in the last 12 hours with the furthermost 9K2OD (4637km) in Kuwait. 63 stations have been spotted on RX.
In this episode, we join Martin Butler M1MRB, Dan Romanchik KB6NU, Caryn Eve Murray KD2GUT, Edmund Spicer M0MNG, and Ed Durrant DD5LP to discuss the latest Amateur / Ham Radio news. Colin Butler (M6BOY) rounds up the news in brief and the episode's fea...
Zu ihrem 60, Jahrestag wird ICOM eine auf 2400 Stück limitierte Auflage des ID-52 herausbringen. Lest in diesem Beitrag was es zu bieten hat. In diesem Jahr feiert ICOM ihren 60. Jahrestag. ErfahrungsgemÀà zelebriert ICOM das mit neuen GerÀten oder limitierten Auflagen von bereits auf dem Markt erhÀltlichen GerÀten. So auch in diesem Jahr: Mit ⦠ICOM ID-52 Plus (Limitierte Auflage zum 60. Jahrestag) weiterlesen