Friday, March 29, 2024

A QRP CW Contact (Video) with the Winterfest MXM SupeRX/TX 40 (1 Watt, Crystal Controlled Transmitter)

I picked this transceiver up at Winterfest for one dollar. 40 meters. Superhet receiver with 455 kc ceramic filter and 2 NE602s. Crystal controlled one watt transmitter on 7039.5 kc. I emailed Jeff KA2BKG and asked him to slide up a bit to my freq. I am glad he did. Thanks Jeff.

5 comments:

  1. Hi Bill,
    Thank you very much for keeping your excellent blog about homebrew radio. While searching the internet for details about your acquired MXM rig, I came across a magazine called ‘Hambrew’. Old but loads of interesting (mostly simple and analogue!) homebrew stuff in there. Look at all those homebrew rigs! I thought you might find this an interesting read. https://www.worldradiohistory.com/Hambrew_Magazine.htm

    73,
    Wout, PE1GXH

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  2. Excellent Fists on both ends of that QSO. Easy copy, the way it should be!

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    1. Thanks for the comment on my fist Mike. It has been a while, but as you know, this is sort of like riding a bike -- you don't forget! 73 Bill

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  3. I wasn't able to find a manual for the MXM rig but did find two articles by Bruce Williams in 73 for a receiver and transmitter which together might be this rig:

    https://archive.org/details/73-magazine-1991-04

    https://archive.org/details/73-magazine-1991-12

    Best Regards,
    Chuck, WB9KZY

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  4. Thanks to Wout and Chuck for the info. I had seen the Hambrew articles -- really helpful. I had not seen the 73 articles that Chuck found. These two articles provide the schematics for both the TX and the RX in my rig. It looks like Bruce Williams went beyond the standard NE602/LM386 neophyte. He has an attenuator chip in there too. And the RX/TX combo provides some very useful sidetone. 7040 seems close to some digital stuff, so I got some 7030 crystals and might QSY to that freq. Thanks again fellows. 73 Bill

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