GM4ULS ham radio station

a QRM-free zone!

Another one bites the dust

Posted by gm4uls on December 2, 2011

I was going to start posting from time-to-time about the odd pieces of equipment I have lying around the shack, in cupboards, and so forth. This seems like a good time to start.

Way back in 1980 I decided to buy an HF rig in order to give myself an incentive to take and pass the Radio Amateur’s Exam. The rig I bought was a Sommerkamp FT-7B – I have already sung its praises, and if I found another one for sale I would buy it instantly. The XYL would frown at more expense of that nature, although she is normally very tolerant (see later in this post). Anyhow, the Sommerkamp is long gone. For quite some time I lent it to a friend, G4EID, then got it back, then it went… hmmm… where did it go? The PSU that supplied its get-up-and-go was a Yaesu FP-12. The FP-12 ran at 12amp, and even had a built-in extension speaker which boosted the audio level and quality from the rig.

I have kept this PSU for many years and have driven all kinds of equipment with it. Most recently it has been used to power my AT5555-N, but just yesterday it went dead just as I put the AT5555-N into transmit. The rig draws no more than 5amp on full mod AM so the FP-12 was entirely adequate to the task. The first step I took was the logical one. I jiggled all the wires, banged the lid, and swore at it I checked to see if a fuse had blown. I checked with three new, just-out-of-the-packet fuses but it was as dead as dead can be. I took the top cover off to see if I could see anything amiss, but everything appeared okay, except for a little dust.

I blew out all the dust, put the cover back on, and switched it on again (that’s the RAF way, folks!) but to no avail. Now I dare say I could devote some time to fault-finding. That would be a voyage of discovery for me, as I am not (I keep saying this) very technical. However, I guess I don’t have the time. So this FP-12 will be going to the guy who erected my MA5B mini-beam, as a donation to the funds for the local 2m and 70cm repeaters. If someone else picks it up at a junk sale and can make it work, then they are welcome to it and the repeaters are welcome to the money. Meanwhile I have ordered a 30-35amp from a radio retailer.

(Aside to my XYL) Yes dear, I know we have just had to buy a new freezer, and I know I have just ordered some new Levis because I’ve lost weight, and I know I said that my AT5555-N and my B300P were my Christmas present and I wasn’t going to buy anything else, and I know Christmas is coming very soon… but on the other hand I have had this thing for more than thirty years, and being without it means I can only run two thirds of my radio gear simultaneously, so I think you’ll agree that… yes… I can buy a new PSU… thank you dear, you are very understanding.


2 Responses to “Another one bites the dust”

  1. Hans said

    Unless the wiring of the transformer failed (very unlikely, but it does happen), the rectifier diodes are the first suspects I would look at. Fast and cheap to fix.

    I hope you ordered a conventionally built PSU instead of a switching power supply. 😉

    • gm4uls said

      I may well have a look at them. As a start, I shall rummage through my papers and see if I have a circuit diagram anywhere.

      The new one is to be an Alinco 340 which is (unless they’re not telling me something) not a switching power supply. See – I do listen to what you say. 🙂 😉

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