Wednesday, July 20, 2016

DX Handy 10m does not transmit on SSB... hints for debugging


one of the issue which can happends on the Mizuho handies is lack of SSB TX as reported by John, W8BCR...

"Ok, so I confirmed my dx handy 10 meter receives, and I confirmed with another radio that it transmits CW. It does not seem to transmit voice. When I push in the PTT, I hear a quick static noise accompanied with a flash of the transmit light but it does not remain on while I hold the PTT in. At this point I can use the built in keyer and transmit CW, but no voice. Any ideas where to start? Thanks, John W8BCR

There are the hints and tips from our family members as follows:

Likewise i have a couple and both obtained cheap as faulty and not receiving. Both had the same problem which is that due to the weight of the xtal filter and its soldered connection on the pcb if the radio is dropped then the filter breaks away at the solder joint and hey presto NO REC.
quick solder job and back in business again .

Hi, I have a collection of nineteen (19) MX radio's , most problems I have encountered have been due to dirty slide switches, especially the SSB/CW change over, blast them with switch cleaner and rattle them up and down until your arm aches.
Peter G0KOK

More details about this troubleshooting you can find on Mizuho and Nishi Musen Reflector by Caitlyn, K9NI over here:

Hope it helps to more owners,

73 - Petr, OK1RP


  1. This is John, W8BCR. I found the problem to be a dirty SSB/CW slide switch. I removed and cleaned it carefully, now it is working just fine.

  2. Hi John,
    great to hear that you finaly fix the issue. Congrats! See you on the air using our Mizuho jewels maybe... 73 - Petr, OK1RP

  3. Hi Petr , great blog. I would suggest cleaning all switches and controls. Do you know if the typical japanes handy mics would work like the Icom hm-9?

  4. John, I am going post the Mizuho wiring. Maybe it will help...