JUMA Amateur Radio Forum

I managed to get the crucial chip and build two units of the voice memory option and the external keyboard. Both units seemed to work (they recorded my speech/RX audio and played it back) and I celebrated... ...until I found out that nothing is broadcasted to RF even the recording is clearly audible ...

Dear all

Has anyone found a reliable source to purchase these microcontrollers? It's absolutely out of stock on major retailers. I managed to get one from fellow ham but I would need another so I could build a lovely TRX-2 for my family member too.

BR,
Joel OH2CBD

I have also replaced T2 with Kemet 542CT. I hope it's suitable replacement.

Dear other hams I was wondering if it's possible to substitute T1 on TX-1 with something self made? On RX-1 this TDK transformer has been substituted with this: http://www.jumaradio.com/juma-rx1/bifilar-transformer-en.html I did similar also for TX-1, BN43-2402 with four turns of bifilar coil. I was ...

Replying to myself in case somebody else is wondering this. HEF4052BT by Nexperia was working properly in my build.

Dear fellow hams I’m having troubles finding suitable part for D1 on RX board. It seems to have quite specific requirements (has to be Philips). I was able to purchase Philips branded but it has label ”PC74HC4052T” so no HEF available. I also got Nexperia ”HEF4052BT”. Would any of these work on RX1?