[Kenwood] TS-850S/AT Power output??? Low??

Thu, 22 Aug 2002 09:37:33 -0300

Hi, guys.

A friend of mine has a TS-850 and the output power was only 1 W in 10
meters.
The culprit was the 74LS145. The pin number 2 was always low.
We put another chip in place and the power went to normal in all bands.
But another problem appeared. I think that it was there before and had not
been noted. The output power goes up and down in a low frequency cycle.
I connected the scope to DRV terminal in TX-RX Unit and the oscilation is
there, even in RX. It starts a few seconds after the rig is turned on, about
1000 Hz and goes down to more or less 60 Hz after 10 minutes. I suspected
that C247 or Q5 were not good. But they were replaced with new units and the
problem is still there. I dont�t understand why it occurs even in RX.
Any ideas? Thanks in advance.

Joe, PY5CEK
----- Original Message -----
From: John Tait <[email protected]>
To: <[email protected]>; <[email protected]>
Sent: Thursday, August 22, 2002 5:42 AM
Subject: Re: [Kenwood] TS-850S/AT Power output??? Low??

>
> Subject: [Kenwood] TS-850S/AT Power output??? Low??
>
> Hi Joe..
>
> My gut reaction is that you have a problem with one of your High pass, or
> Low pass filters.....Or the control circuit that selects them...i.e.
> the74LS145 decoder chip.
>
>           Good luck with it OM
>                73
>                   John EI7BA  http://www.iol.ie/~bravo/
>
>
>
> > I bought my TS-850S/AT new about 10 years ago.  Out of the box 10 and 15
> > meters power output was low.
> > About 70 and 80 watts.  I adjusted VR7 on the RF Board for 100 watts on
> > 10 meters and all was well.
> >
> > But during the SARTG RTTY contest last weekend when we had some activity
> > on 10 and 15 meters, I noticed that
> > the output on those two bands were lower than normal. So I borrowed a
> > Bird Wattmeter so make sure of the
> > readings.  I tried to adjust VR7 again, but there was no increase in
> > power.  This what I measure. I wonder
> > if other 850 owners have about the same output as I?  Is there anything
> > besides VR7 to adjust??
>
> >
> > Power Control Full CW, Carrier Control Full CW, Mode FSK, all set from
> > the front panel.  Bird wattmeter and Heathkit dummy Load.
> >
> > 28.500 MHZ  85 Watts
> > 24.850      90
> > 21.225     110
> > 18.100     120
> > 14.175      94
> > 10.115     160
> >  7.150     155
> >  3.775     155
> >  1.850     180
> >
> > I have almost never operate below 20 meters, but when I do, I always set
> > the carrier for 100 watts or less.
> >
> > Any Help or suggestions?
> >
> > Joe K0BX
> > - - -
> >
> > Your moderator for this list is:
> > Larry Wilson KE1HZ [email protected]
> >
> > _______________________________________________
> > Kenwood mailing list
> > [email protected]
> > http://mailman.qth.net/mailman/listinfo/kenwood
> >
> >
>
>
> ---
> Outgoing mail is certified Virus Free.
> Checked by AVG anti-virus system (http://www.grisoft.com).
> Version: 6.0.381 / Virus Database: 214 - Release Date: 02/08/2002
>
> - - -
>
> Your moderator for this list is:
> Larry Wilson KE1HZ [email protected]
>
> _______________________________________________
> Kenwood mailing list
> [email protected]
> http://mailman.qth.net/mailman/listinfo/kenwood