TenTec Model 1054 Shortwave Radio Kit - The Latest Update

A couple weeks ago I posted an update about the TenTec model 1054 regenerative shortwave radio kit I had built a while back. As regular readers will recall, this radio had issues with the regeneration control not working smoothly. And after a couple unsuccessful attempts at contacting TenTec's service department, I finally got an answer. One of the techs said he'd send me some replacement components to hopefully fix the problem. Here's what happened:

I installed the two new FET transistors and trimmer potentiometer the man sent. Upon testing the radio post repair, the problem was exactly the same - perhaps slightly worse. I calibrated the bands by setting the regeneration control to full oscillation and listening for that signal using a borrowed shortwave receiver. In doing this, I made another discovery:
The sensitivity of the TenTec 1054 was grossly inferior to that of the borrowed radio.
On the borrowed radio - using ONLY a 12 inch cliplead for an antenna, I could CLEARLY hear the WWV time signals on 15 MHz and 10 MHz. On the TenTec, using a 20 FOOT longwire antenna - no sign of WWV. I have always said that if you can't hear WWV on a shortwave radio, you won't hear much else, either. Indeed this was the case. The TenTec could pick up China Radio International, some strong Spanish-speaking stations and a couple strong religious broadcasting stations, but I could not pick up ANY ham traffic. Again - the borrowed rig could get a few ham stations even with a foot long cliplead as an "antenna".

Lest anyone think that maybe something got messed up during the repair, I want to emphasize that I had NEVER been able to hear WWV, or more than one or two ham stations, on the TenTec radio. Prior to having access to a decent quality receiver to check it with, I simply chalked it up to not being able to determine where the unit was actually tuned.

One final test - I took the TenTec to my friend's house. He has a 100' longwire antenna and a good ground system. ONLY by doing this was I able to hear WWV and a few hams. But the WWV was NOT strong as it should be - in fact it was rather faint.

I have built regenerative radios in the past and while they had relatively poor selectivity compared to commercially built superheterodyne receivers, sensitivity was NEVER an issue before.

In view of the sensitivity issue, I think I will NOT invest any more time, energy, or money in this project. The return is simply not there.

What I think I WILL do is when I have the funds, find an older "classic" shortwave radio, buy it, and restore it. For that matter this would NOT be a bad way to get good ham gear, too. The new stuff is entirely too expensive. And once you have restored a radio you would know intimately how it works and how to maintain it.

And as an added benefit - older vaccuum tube gear would tend to be fairly EMP proof.

TenTec Radio Kit - Model 1054 Update #3

My longtime readers will remember I built a TenTec Model 1054 regenerative shortwave receiver kit a while back. At the time I posted to this blog about the apparent bad customer service I received from TenTec when complaining about the erratic regeneration control. Just week, there has been another development.

This past week I have been working feverishly to get all my ham and shortwave equipment up and running. After an exhaustive and *fruitless* search online, trying to find any information I could on the TenTec 1054's regeneration control issue, I decided to try once more to contact TenTec's customer service people. TenTec apparently has NO PHONE number to reach them at; apparetly one must email them as I had before. And so I did.

The following day I got an email back from one of their service technicians stating that my original email had gone into his email "spam folder". He also stated, contrary to the instruction manual, that the regeneration will start 1/4 of the way from one end of the potentiometer's travel, that regeneration will start rather suddenly, and that from my description the radio seemed to be working correctly. ANOTHER tech later wrote me and said that he thought there was a defect in either one of the two FET transistors in the regeneration circuit or that the regeneration threshold adjustment trim potentiometer was bad. He offered to send me new parts free of charge if I sent him my address. I did just so; I'll see what happens.

If they do not end up sending me the parts (I'm NOT holding my breath, under the circumstances), after studying the schematic at some length I have some ideas as to how I can modify the circuit to work better.

All this said, I still have the issue of what to do about the housing, since the box TenTec sent me is basically unusable. As mentioned in my original post I intend to do some circuit modifications such as adding a dual 9-volt regulator circuit that can be fed from an external 12 volt battery, and possibly adding a band spread control for better selectivity in crowded bands. I want to build my own improved audio section based on a decent audio chip. I would also include an active filter for CW reception and a limiter to prevent hearing damage from loud noises. Regarding the dual 9-volt regulator, the circuit currently uses separate batteries for the regenerative receiver itself and the audio section. This is no doubt to eliminate any issues from feedback and oscillation between the radio part and the audio section. But for my purposes I need the whole thing run from one 12 volt battery.

Here are the links to my prior posts regarding the TenTec Moel 1054 radio:

http://inkarlslab.blogspot.com/2011/04/ten-tec-short-wave-receiver.html

http://inkarlslab.blogspot.com/2011/05/ten-tec-model-1054-shortwave-radio.html

Book review: Radio Receiver Projects You Can Build

This is one book I heartily recommend for anyone interested in amateur (ham) radio, shortwave listening, or general electronics. I have owned this book for nearly 10 years and have actually built my own variations of a couple of the projects shown. This book covers crystal radios, tube type regenerative receivers, transistorized radios, solar powered radios, and more. This book contains good, solid, practical construction advice and tips for both newbies as well as more seasoned radio hobbyists.

For years I have wanted to try my hand at building an old-fashioned one or two tube set like old radio hobby magazines used to describe. This book contains those. If you want to build a solar-powered transistorized radio, the information is there.

Whether you are a father wanting a nice father-son (or daughter) project, or you are an aspiring ham radio operator, or a prepper wanting a simple EMP-proof tube radio that you can build and repair yourself, this book is for you. I bought mine at a brick-and-mortar store almost 10 years ago; they are available online at Amazon.