I would like to share a literally untapped source of commercial SSB/CW transceivers that can be retrofitted as modern ham transceivers.
It is no big secret that many commercial SSB radios can be made to work, and nicely I might add, on our ham bands. Yet there doesn't seem to be a lot of information on specific radios and details of the conversions.
Radios that are great candidates often are the ones operating in the 2 to 12 MHz range and Crystal controlled. These are often really cheap, because they are not frequency agile, (read crystal controlled) and not on the top of the want list. Many Marine SSB radios are also good candidates and have direct frequency entry. SEA has marine radios listed on eBay and that cover from 80M through 15M and have the direct frequency entry. Don't overlook the Collins AN/PRC-47 which is that same 2-12MHz, 20 Watts, USB topology.
Eleven years ago, I spotted a Ten Tec Model 150A, 8 channel, 2-12 MHz SSB/CW radio for less than $100. It is a 100-watt radio, all solid state, has selectable sidebands and a noise blanker. It was in operational condition... I did the buy it now!
The Manual for the Ten Tec Model 150A is HERE.
TT Model 150A W/N6QW Mods
.webp)
SEA Marine SSB
.webp)
SEA Direct Entry Radio
Northern Radio 12 CH Marine Band
Back to the Model 150A... This is not a conversion that can be undertaken by the typical newly minted/anointed 45 Minute Extra as you really have to have a significant background in electronics to be successful in the conversion. Let me explain.
The 1st approach was to have an 160/80/60/40/30/20 Meter radio under the control of a remote-control box as seen below. The box had an encoder and also you could up/down tune the radio using two of the keypad keys. The 8X2 LCD gave you all the info you needed to operate the radio. You could also choose the step tuning rate via the keypad.
Remote Control Box
This conversion had to be "engineered" as no one had done this before to this radio (as far as I know) and it was not some kit to be installed.
The tasks were many, starting first on how to generate the code for the digital LO so Key #1 = 160M and so on. Following that, how and where to inject the Digital LO and BFO signals into the Model 150A.
Now the radio had 8 channels that you could select via a band switch (BSW). But that BSW also selected a bank of band pass filters so that position 1, liked the 2 MHz frequencies and position 8 was for the 12 MHz frequencies. A matrix in the manual identified the correlation. The first problem here was to take the Position 8 filter which maxed out at 12MHz and move that to 15MHz to cover 20M. Lots of time was spent with LT Spice to find the filter constants. I changed those constants while the boards were installed in the radio.
I mentioned that the Model 150A had selectable sideband (USB/LSB), there was even a front panel switch for that selection. But USB was standard for these commercial radios and LSB was optional. No, it was not a matter of finding a LSB BFO crystal as TT used the separate USB and LSB filters with a common BFO frequency. The Filter CF was around 12 MHz. I tried to find a 12MHz LSB filter... no luck. On a posting to a reflector one ham worked on commercial SSB products and he sent me a matching USB/LSB set of filters at 16MHz. I popped those in the radio but some of the IF stages couldn't be twizzled to cover 16MHz.
The Model 150A filters were not the stock ladder type you see in the Ten Tec ham radios but were from Network Sciences in Phoenix. A call to that company actually found the guy who designed the 12 MHz filters, and he told me that the filter was so good you could use two separate BFO frequencies... you just had to find them. I did and the Si5351 generates two BFO frequencies that are panel selected.
I soon found that the remote-control box was like in the Rhyme of the Ancient Mariner... an albatross around my neck. I 68'd the box. BTW the term 68 is from the Mafia. You bump the guy off and bury him 6 feet down and 8 feet away.
The next step was to build the digital LO inside the Model 150A and make it a tri-band rig, 80/40/20M. The Model 150A had a front facing internal speaker which I removed and used that space for the Digital LO/BFO.
Tri-Band Model 150A
The board for VOX and CW was not installed, but I do have the schematic and could fab a board, but this is not a burning issue for me.
It is so nice to have a modern tri-band rig with amenities like selectable SSB, Noise Blanker, Digital LO, 100 watts and all solid state. The total bill after modifications was $150 including the radio.
Them that know, can make it go. There is a 22-page document I prepared covering the nuts and bolts of how to convert the Model 150A. If you would like a copy, then send me an email to my QRZ.com address. This document has the LT Spice simulations and was made when the Keypad was the control medium.
If you read the document, then you will see that knowing the techie side of the hobby makes possible the creation of radios useful on today's bands and for little money. This is where ham radio started and the now "no need to know anything technical license" is killing the hobby. The Model 150A Remote Control Box adventure was the seed that enabled me to grow a Remote-Control Box for the Triton II as seen on the https://www.n6qw.com website.
.jpg)
73's
Pete N6QW
