Monday 4 July 2022

Neophyte Twins - An Update


Blog readers may recall my last two construction projects, the ‘Neophyte’ 1-tube regenerative receiver and a matching ‘Neophyte’ 1-tube crystal-controlled transmitter. The receiver turned out to be an exceptionally good performer once some slight tweaks were made to the original design published back in 1968.

It worked so well that I then decided to build a simple 1-tube transmitter to physically match the receiver and put together another circuit from the 60s using a 5763. Once I had the pair working well together, I set myself a goal of Worked All States on 40m CW with the tiny pair. I had a tremendous amount of fun during the cold winter nights and slowly worked my way through the list of states, eventually working and confirming all 50 states.
 



When the winter of ‘21-‘22 rolled around, I did another silly thing and set the goal of yet another Worked All States, this time on 80m CW which would offer a much bigger challenge for the little pair.
 
Over a period of about 7 months I once again managed to work all 50 states, mainly all on 3560kHz, with most of the contacts being made shortly before or shortly after my dinner hour of 1800 local time. There turned out to be a lot of good ears out there and fine bunch of great CW ops, all able to pull my signal through the noise. It was fascinating to hear the difference in propagation from one night to the next while operating at the same time period each night. Most nights produced no new states as they seemed to come in bunches, with December 9, 2021 being particularly good, producing IA, ID, MI, ME, PA and AL, while February 21, 2022 brought NH, MS and AK.
 
After working all 50 states, it took several more weeks to gather all of the prized cards.
 

80m WAS QSLs - thanks guys!

Looking back at the past two winters of nightly CW fun, it’s nice to recall just how much pleasure was derived from such a tiny investment in construction time, let alone cost. Everything, including the unused mini-boxes, was found in my parts collection with the exception of the 5763 tube in the transmitter. My junk box has been growing ever since my interest in radio began as a pre-teen back in the late 50s, smitten with the magic of radio. Fancy multi-thousand dollar radios offer truly amazing performance, but for me, can often make things too easy, removing much of the magic.
 
Next winter’s new one-tube project, circa 1936, is now in the mock-up testing phase and should provide some challenging DX fun on 10, 15 and 20m as Solar Cycle 25 breaths new life into the higher bands … stay tuned for an update soon!

9 comments:

Anonymous said...

Amazing - 73 - Dave - KS9H.

Anonymous said...

Great job! - Stan, K3PW

Anonymous said...

Very excellent work Steve

Anonymous said...

Kudo's to you Steve! What an accomplishment of both your operating and construction skills. Love the look of the pair. I have a nice memory of the 5763 tube from my teenage years. It was the final tube in my Lafayette Comstat 25-A base rig on 11 meters. CB was fun back in the '60's, where I grew up. Sort of like ham radio, but the ops weren't quite as technically minded. Just a nice group of people who liked to chat on the air in the evening hours.

73

Anonymous said...

I am in the process of building a Neophyte 1 Receiver but have been unsuccessful to find the details for the winding of coil L1. Can you assist? I am primarily building it for 40M. I am adding a 6AQ5 audio amplifier. de WA9GUS

Anonymous said...

Hello WA9GUS. The article on my main web site has a link to the original article but I’ll provide it again for you below. The coil used will cover 40m but it is not critical as the coil winding data will depend on the diameter of whatever form you choose. Since I chose old bakelite tube bases, I wound for the inductance needed to cover the bands needed with my particular capacitor so it’s best just to calculate for your own case. It’s very easy especially if you have something that you can measure inductance with. There is a LOT of audio that comes from the audio stage so you really don’t need another AF amp for the Neophyte and if you do add one then it’s no longer a Neophyte ;-)
Good luck with your project and I hope you have as much fun as I’ve had with mine!

Anonymous said...

https://qsl.net/ve7sl/neophyte1.pdf

Anonymous said...

Still in the process of making my “Neophyte” receiver operational. I added the recommended single turn on the coil to accommodate antenna input to an SO239. My question is where the bottom of the single turn was to be connected to the top of L1 which would make sense but doesn’t seem to change anything. Going to ground is the alternative. I was also going to try to replace the 10pf antenna input cap with a 15pf variable cap that was the antenna input cap to an ARC-5 receiver. Even though I have isolated it from ground, touching its knob mutes the receiver. I may put the 10pf disc cap back in. So far, haven’t heard anything on it before adding the antenna input winding, but haven’t been able to connect it to an outside antenna. WA9GUS

Anonymous said...

The single-turn antenna link is not connected to the main coil. The top end of the link connects to the SO-239 center pin and the bottom end goes to ground. On the SW coils, I put the link on the top of the coil form and am able to swing it up or down to vary the coupling.

Try to get things working well on the AM BCB first before going higher in frequency. You should hear a LOT of signals using the antenna coupling capacitor input and just a short few feet of wire but anything like a longwire will be better with a smaller coupling capacitor. Feel free to e-mail me directly rather than via the blog comments which I could easily miss.