I’ve had this Kenwood TM G707E Dual Bander for years. It rarely gets used and has been just stuck in the shack for a long, long time. Last year, due to all the noises, pops and bangs on HF I was getting at the time I decided to put it into to the car permanently. Brought a new dual band antenna and mount and hey presto G8YPE/M again.
Things were good, not many contacts but I could get into a variety of repeaters on 2m and 70cm around and about. When I finished working for the day I just removed the control head and replaced it the following day I set off for work.
No problems until I went to Turkey. Now, Turkey has nothing to do with this post, but, my problems started when I came back from holiday/vacation or so it seemed but it could have started before then.
I tend to monitor while I’m working, the car is my office, I make 70 or so stops a day serving my customers. QSOs could therefore be quite short and to be fair if you have been on 2 or 70 in Birmingham you do do a lot of monitoring of nothing since the demise of the GB3CB repeater, I do miss that box… Anyway I digress, the mic is raised occasionally and I was getting confused that repeaters were not opening and that people were not responding to me. I then looked at the head and pressed the PTT, the S meter kicked up and the radio went back to receive. Not good. Checked the settings, tried simplex, tried another microphone, same problem. Reset the radio, cleaned the contacts on the control head, checked the fuse, the lead, the power lead from the battery. All OK. Still no transmit.
Now I remember the good old days, I’ve been licensed since 1980, years of cold winters before too and I know that some of the older PYE mobile transceivers would refuse to work, until warmed through from the car heater. Could it be the temperature? I checked the specs of the radio good for -20C, it certainly not that cold of a night….. Currently.
I left the radio in the car, as said I used it as a monitor receiver so no big deal no transmit. Occasionally, it would transmit, but it would stop working mid contact so the radio was eventually taken out and put on the bench. Put it on the 12V PSU and hey presto full 50w every time I transmit, every time.
So what was wrong. I had checked everything. Full 12v in the car, everything checked out and I’ve always seen a dimming of the display lights as a sign of a unit dragging volt down as power is used and the lights were not fluctuating but that what was happening. I had a connection block inline so I could change radios in the car, one day all radio DC leads will be the same, that connector must have been bouncing around and the lead was not making good contact anymore as the screws were a little slack when I took the radio out. Obviously enough connection for 12v for receive but not enough amps for transmit and the radio must of sensed this and popped itself back to receive. Now if only the lights had gone off instead. Oh, for the good old days.
I mentioned the pops, whizzes and bangs on HF, I’ve just changed my broadband hub, it’s all of a sudden so much quieter on HF all of a sudden. I really hate radio……Sometimes.