Showing posts from June, 2021

Yaesu FT-100D Repair [2], SRF7043 Crack

The FT-100D which I bought last week “for parts or repair” has some issues. I documented those issues in the last post. I have sone some work and have halfway fixed one problem. There was a short which was drawing around 8 amps continuously, all signs pointed to a problem with one of the final transistors. There was a part which had been soldered to the ground plane near the SRF7043 VHF/UHF final amplifier. When I desoldered it, I could see the surface of the SRF7043. After a little cleaning I noticed the dreaded cracking which has happened to a lot of FT-100D radios. I researched and asked in a FT-100 owners group about this and decided to remove the SRF7043. Once I had removed the final amplifier I put power back to the unit and now I no longer have a continuous 8 amp draw. There are no more SRF7043s easily available as replacements. There is a guide by VK3BKC on replacing the SRF7043 with the MRF1570N. The MRF1570N is not a drop in replacement the width of the device is about the s

Yaesu FT-100D repair [1], Something is Screwed up

 I just purchased a "for Parts or repair" FT-100D, from the estate of a silent key. There are some things immediately identifiable as problems.  1. The Microphone cord rubber has completely disintegrated. This is super common, it seems pretty much all of them do this. All that should be needed is a replacement cord. 2. The fans are tied together and connected to a 12V cigarette light plug. So the radio has either no fan or full power fan all the time. It's quite loud. 3. On power on, the unit draws 8 amps all the time. 4. There does not seem to be any transmit capability on any band. The most concerning thing at the moment is the 8 amps on power on. I don't want to further damage the unit. I need to find the source of the short soon. While opening the unit to inspect it one of the screws stripped and I could not remove it. Come in the reverse direction drill bits. They are very useful and have helped me remove a few very stripped out screws. I first drill a small hole

Yaesu FT-5200 YSK-5200 YSK-1L Separation Kit Alternative

                                                              I was asked to make a separation kit for the FT-5200 by a customer for the FT-100 kit. I told them, send me the radio and I will make one for you. So I have! It uses the same connector adapters and a custom 3D printed mounting bracket. It also has a quick release on the side for easy removal just like how you would remove the head from the radio body. The actual name of the original kit is the YSK-1L. If you would like one or have a radio you would like a separation kit for that I have not made yet, email me at