[Kenwood] Re: TS-830 unstable ALC and burned R37

[N6WK]

Thanks Jim for the kind words. I am only happy that we were able to 
finally figure it out.
Now that the 830 is up and running as it should, maybe we can work on 
the air one day. That would be nice.
You are a better Tech then you give yourself credit for !
BTW, I am feeling better today !!
73 and Good work !
Gordon
N6WK

James Barrie wrote:

> I'm posting this as a FYI for all ....
> IT W A S THE RELAY ON THE AF BOARD
> Ok so iI tried to get the cover off of this thing and I couldn't do 
> it. SO, I set the spray can of DeOxit to heavy, pulled back on the 
> cover as much as I could with a dental probe, and sprayed the hell out 
> it right at the edge of where the cover and the relay meet.
> I turned it on and it worked. Nice and stable ALC drive, with the grid 
> going from -43.55 to PLUS 4.56!!!!
> The car control is now set at 3.5 ... never been that low. And 
> microphone is setting is just 4. Got a great report on MIDCARS . In 
> fact they had me back off the mike gain even more. Mike is the MC-60 , 
> set at 500 ohms and the pre-amp OFF.
>
> SO ...
> I think we were chasing two problems. The burned up R37 on the RF 
> board was the result of R11 on the rectifier board going high. As soon 
> I replaced R11, R37 has stayed in one piece.
> The ALC issue had nothing to do with R37 and R36... but everything to 
> do with the relay. I'd sill would like to know what was going on with 
> the solder marks I found where the relay is soldered onto the AF board 
> ... and why R36 - a 1 meg ohm R36 , not a 100k - was tack soldered in 
> to begin with.... oh well. Since i am not the original owner, and it 
> was bought from R&L, who knows. But it works great now ...
>
> Oh, and by "we", I don't mean the infamous ham radio 'We".
> Thanks to Ken, K4EAA who first responded and gave me ideas and a hell 
> of a good, readable schematic.
> Russ, WB8ZCC for more advice. He'll never read this since he doesn't 
> have any Kenwood, but thanks anyway, Russ
> AND FINALLY Gordon, N6WK who endured something like 46 or so emails 
> and responses over the last 3 or 4 days. His patience and direction 
> was really what got my 830 s back and up and running. He did this 
> while sick with a cold.
> THANKS GORDON for all the support. I'm not the best tech in the world, 
> but I do try. Gordon was REALLY patient LOL
>
> 73
> Jim
> WA8SD
> On Feb 7, 2007, at 1:19 PM, James Barrie wrote:
>
> ok, this is a continuation of the unstable drive issue with my 830.
> thanks for the advice on how to get to the bottom of RF board.
> I replaced the burned up R37 and the high R36 and fired up the rig. 
> The unstable drive
> continued and while in the tune position, R37 went up in smoke again.
> Checked all the voltages on the 12BY7A while on receive and transmit 
> and found the
> following:
> screen is 234 on receive and 191 on transmit
> grid : - 44.3 - receive and -4.93 to - 7.63 transmit
> cathode: ZERO on receive and 1.6 to 1.7 on transmit
>
> also checked R34 (99.8K), R41 (69.7), R35 (112.3) and R27 (387.9).
> The 12BY7 was tested good on a tube tester, but that may not prove 
> anything ....
> Still getting 125 watts output.
> Anyone have any suggestions as to why the grid is not going positive 
> and the cathode is
> not getting to 4.6v? Or is there another reason for the unstable drive 
> and large current
> through R37?
>
> thanks,
> Jim
> WA8SDF
>
>