[Amps] Ameritron AL-1500 Problem

[Mike Schatzberg]

Jose:

Check the cable between the transceiver and the amp, or just replace it.

If this does not help, find the T/R relay in the amp, and clean the
contacts.  The relay contacts may be quite poor from hot switching.  The
high SWR at the input, gives a clue that the relay may not be closing and
switching properly.  Notice if the output contacts have been bent to cause
them to connect first before the input contacts close.  This is the
mechanical fix often used to avoid hotswitching the amp relay.

Naturally, check all the connections at the relay as well, perhaps there is
a cold solder joint there in one of the coaxial cable connections.

The fact that the amp worked perfectly, then didn't, then did, leads one to
believe that you may have a maintenance problem with the relay.  I always
change out the open frame relays to vacuum relays to avoid such problems
which arise eventually from the hotswitching.

73 and Happy Dxing,

Mike Schatzberg
WB2AJI
----- Original Message ----- 
From: "Jose E. Ribeiro Sa" <zemurtosa at mail.telepac.pt>
To: "Keith Dutson" <kdutson at sbcglobal.net>; <amps at contesting.com>
Sent: Wednesday, October 05, 2005 10:09 AM
Subject: Re: [Amps] Ameritron AL-1500 Problem


> Thank you Keith
> Yes I just tested it with a second tranceiver and its the same.
>
>
> 73   Jose  CT1EEB
>
> ----- Original Message ----- 
> From: "Keith Dutson" <kdutson at sbcglobal.net>
> To: <amps at contesting.com>
> Sent: Wednesday, October 05, 2005 1:31 PM
> Subject: Re: [Amps] Ameritron AL-1500 Problem
>
>
> > Sounds like a TR relay problem, such as sticking or intermittent ground.
> > Have you checked the TR connection from the transceiver?  Do you have a
> > second transceiver?  If so, does the problem continue with the other
> > transceiver?
> >
> > 73, Keith NM5G
> >
> > -----Original Message-----
> > From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com]
On
> > Behalf Of Jose E. Ribeiro Sa
> > Sent: Wednesday, October 05, 2005 8:19 AM
> > To: amps at contesting.com
> > Subject: [Amps] Ameritron AL-1500 Problem
> >
> > Good afternoon
> > Maybe some of you can give me a clue about this problem Iam experiencing
> > with my Ameritron AL-1500 amp.
> >
> > A couple of days ago I switched on the AL-1500 and when I started TXing
> > there was no output power at all (zero watt), the HV was OK (3300
Volts),
> > but no IP and power mesurements in the meter. Theres an ALC reading.
> >
> > I thought in could be some kind of bad contact in the 8877 lamp so I
took
> > it
> > off cleaned the lamp socket metal contacts put in on again and the
Linear
> > amp. was working ok at full power. === so far so good ===
> >
> > Next day when I turned it on is WAS NOT TXing again, the problem was
still
> > there but after some tries the amplifier started transmitting at full
> > power
> > again and worked all day long.
> >
> > This morning again the same, but this time its not transmitting at all,
I
> > tried to to see if I could detect any malfunction but nothing, all seems
> > OK,
> > the amp. seems to be working ok, but no Power out no matter what I do.
> > I also noticed that the impedance between the radio and the amp has
> > changed
> > because SWR in the radio is way too high (and before the match was
perfect
> > without SWR).
> >
> > I will apreciate your feedback and ideas about what might be originating
> > this problem.
> >
> > 73   Jose  CT1EEB
> >
> >
> >
> >
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>
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