[TenTec] Pegasus TX problem redeux

[Jeff Griffin]

Thanks for the info Duane. The relay's are switching(clicking) as I switch
bands. And appear to be working properly, or just as you described. I also
noticed today that the heat sink get's very warm when the Peg is turned
on(on any band) and not transmitting. I just measured the current, while
idling, it's pulling 7.5 amps at 13.8 volts. It's going to be a rainy
weekend here on the eastcoast, and I'm off for 4 days, looks like I have
found something to do!

73 Jeff kb2m

----- Original Message ----- 
From: "Duane Grotophorst" <n9dg at yahoo.com>
To: "Jeff Griffin" <kb2m at arrl.net>; <tentec at contesting.com>
Sent: Thursday, May 22, 2003 12:26 AM
Subject: Re: [TenTec] Pegasus TX problem redeux


>
> --- Jeff Griffin <kb2m at comcast.net> wrote:
> >   I'm having a strange problem with my Peg. I
> > noticed that it wouldn't transmit on 17 to 10
> > meters, even though the red tx light was on, but no
> > RF. 160 to 20 meters transmitted FB.
>
> Can you tell if the low pass filter relays are
> clicking like they should be when you go to those
> bands that do not work?
>
>  I was testing
> > this morning to see if the Peg was pulling current
> > even though it wasn't putting out RF. I set the
> > power out to 20 watts or so I found that it is
> > pulling 18 amps or so,but not putting out any RF on
> > the bad band's.
>
> There is no way it should draw 18 amps when set for 20
> watts output, - unless perhaps there is a real bad SWR
> situation. If the low pass filters are not switching
> in properly this could account for both the high
> current draw and no output.
>
>  On the good band's it is putting out
> > 20 watts or so into a dummy load and pulling about 7
> > amps. All with a carrier mode. I was surprised to
> > note that for a time  the problem existed only on 12
> > and 10 meters! 17 and 15 meters were  working. A few
> > week's ago it started working on all band's, then
> > went back to 160 to 20 meters. Does anyone have a
> > clue as to what might be going on?
>
> This would be consistent with a low pass filter
> switching problem, 10 & 12 meters use the same low
> pass filter and 15 & 17 meters share another. Since
> these bands are paired you will not hear any relay
> switching between 10 and 12 meters or when switching
> between 15 and 17 meters.
>
>  What I'm looking
> > for is a single point of failure in the 10m to 17m
> > area of the band pass filter, but then I remember
> > that it also worked for a short time on 10/12m AND
> > 160/20m! I'm having trouble reading the schematics
> > as I don't have a very clear copy of them.  Now it
> > is transmitting on 160 to 20 meters again. I just
> > took it apart and looked for cold solder joint's,
> > didn't find any.  Thanks in advance, for any useful
> > suggestion's.
>
> From what your describing I don't think it will be a
> "single point" of failure but I think your on the
> right track. If you haven't already you may also want
> to take a close look at the pin/header connection/area
> from the main board to the low pass filter board.
>
> Duane
> N9DG
>
>
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