My precious FT-817 still is lying around in the shack unable to transmit. I’ve studied the service manual and did some measuring around in it. Regular readers of my blog know that a while back suddenly my Yaesu broke down due to shortage. It seems like a capacitor on the voltage input blew and took something with it. I let the input fix by a local service shop but that alone cost me already 75 euro’s. So now the Yaesu is able to receive again, but still no transmit.
My intention is to fix that myself. The local repairman told me it’s probably due to blown finals that the rig isn’t transmitting. That would make me a member of the “Blown Finals Club”. But I’m not quite convinced by his story. When only the finals are blown, you should get a very faint signal as output. But there is absolutely no signal at all. Not even when I take another receiver and poke around with that antenna in the transmit line of the Yeasu, no signal at all. So maybe the oscillator or driver stage must be (also) broken to get this behavior.

This would be my very first big repair job, there for I’m not in possession of various measuring equipment. The only measuring device I have is a multimeter. That won’t bring me very far in this case. Fred, PA3YH has a Multimeter which can measure HF-signals. A RF-millivolt meter, such as referenced to in the service manual. But it has a maximum reading frequency of 100 KHz. The RF-millivolt meter reads like 2,6 volts AC on the output of the oscillator (the service manual says it should be 66mV). But the output signal from the oscillator has a frequency of 65.875 MHz. So it’s logical the meter is not reading the correct voltage.
Okay, so I don’t know if the output of oscillator is correct, but I DO know that the oscillator has output! So I guess now I should look to the first driver stage.
But I think I’ll look for someone with a good scope first. It’s easier to check all the checkpoints in the service manual and also check if they have the correct value.
If anyone has good tips on how to find the problem, let me know!

Some time ago I’ve bought the TCXO-SO-2 option (Temperature Compensated X-tal Oscillator) from Joerg, DL6IB. Although I was very pleased to have the option, I postponed the installing because I wanted to figure out a way to measure the stability improvement before and after installing. Since I don’t own (yet) a frequency counter, I didn’t know a way to check.
A few days ago Joerg again send me a message asking me if I already installed the option in my Kenwood TS-850. I was a little ashamed to reply I didn’t. Promised him and myself to do this as quickly as possible. At this new years day I’m a little tired anyway, didn’t feel like anymore work around the house. So I sat down and opened my TS-850. Before I started with installing, I googled around to find a story of installing this option. Didn’t find anything. Okay, it is a pretty simple install but it gives me confidences to read about it. Seems I have to post the first story about installing this option… (more…)

Okay, it took a while but I’ve finished the voice keyer project! The last article about this voice keyer I’d receive the wrong package. The second time I did receive the correct PCB but the programmed GAL-chip was a 20-pins one instead of a 16-pins. After receiving the correct GAL-chip there was another problem. When I put on the keyer, all the leds where on and when I pushed one of the buttons, the led went out. Exactly the other way around from what should be… Another good look at the circuit learned me that you never have to trust a part list on its own. Always double-check with the circuit before ordering parts. The 5 transistors in this keyer should be (according to the part list) the NPN BC547. But at the end the circuit told me otherwise: 4 of them should have been a PNP BC557.
So after re-ordering the new transistors, the keyer works great! The sound is good, the handling is just perfect! I’m really happy with the result. I don’t know if the casing in the pictures will be the final one. Maybe I build or buy something nicer. But for now it’s fine! The next contest I can relax and listen!

It is a really simple and cheap to build voice keyer. For something around 40 euros you’ve got it up and running (of course without casing).

I will write an article about this building project for our club site soon. There will be circuits and PCB-layouts attached. But first I have to get permission from the original designer. Will announce here when it’s published.

Since I am a relative new amateur, I don’t yet own many devices where I can do measuring with. Of course I have a multimeter and some old analog CB swr meter. But I like to have a better equiped shack. When I take a look in the online shops or at the flea-markets, I’m shocked about prices for a good SWR-meter or a simple frequency counter!

It must be possible to find a good but cheaper solution, I figured and fired on my favorite browser. After a few minutes of surfing I did find this very interesting link:

Digital Power & SWR meter from OH2NLT.

After reading this article I’m very interesting in building this device. So I went on part hunt. Most of the parts are easy to buy but the display is very hard to get a hold on. The solution appeared very easy: just send an e-mail to Matti OH2MH and he did send me a display in about 2 days!

So now I need to collect the last parts and start building… I’ll keep you posted!