Jose',
You may have already done this, but a good test to isolate problems
in the amplifier from the exciter is to key the amplifier manually using a
shorting plug installed in the amplifier's T/R control jack. If the receive
does not come back after you remove the shorting plug (unkey the amp)
then I would suspect that the problem is in the amplifier. The other thing
I would do just to make sure that there is no problem in the exciter, is
try connecting the antenna directly to the exciter when the RX goes
away. This will confirm whether or not RX path is opening up inside
the amp or inside the exciter.
Good Luck!
73 de Mike, W4EF...........
----- Original Message -----
From: "José de Sá" <ct1eeb@mail.telepac.pt>
To: <jari.jokiniemi@nokia.com>
Cc: <towertalk@contesting.com>; <amps@contesting.com>
Sent: Thursday, December 20, 2001 10:27 AM
Subject: [AMPS] Re: AL1500 problem
>
> Hello Jari and friends,
> I have just done as you said and put in a ferrite
> in the relay line (4 turns).
> I still have the problem.
> It is curious that when I had a setup with an FT-1000MP
> connected to this Linear I had the same problem in reception,
> at that time I told Martti OH2BH (because the FT-1000MP was his
> radio) that the radio had a malfunction, now I see I was wrong because
> the TS-870 behaves in the same way.
>
> Iam still trying to figure out whats wrong, but Iam glad because I got
some
> replies
> and I will try to check out.
> Here are my conclusions:
> - Spite it looks very much to be a radio problem (radio relay maybe)
> Iam confused because the Yaesu FT-1000MP also had the same problem
> as my TS-870 is now (with the same Linear), nevertheless when I turn
the
> Linear OFF completelly the problem remains until I press PTT and then
it
> doesn't returns if the radio is ON with the Linear OFF. (once again the
> same
> hapenned with the FT-1000MP).
> - The Linear Amp (AL-1500) relay and fast QSK board are brand new.
>
> ---> Something that I will check-out now are the PL connectors, but I
solder
> every connector (I don't cramp them).
>
> By the way I also used an Acom 2000 Linear amp. before and this lowering
> in reception strength was NOT a problem.
>
> Any further ideas about how to get this problem solved will be most
welcome.
> For those of you that haven't got my original mail please read it below.
>
> 73
>
>
> Jose CT1EEB
>
>
>
> Hi,
> I have purchased a Ameritron AL-1500 amplifier 4 years ago and
> for the last year it has developed a problem that I hope
> you can help me solve.
>
> A) When transmitting and returning to reception, the
> reception signal strenght in the radio lowers dramatically and it
> only returns to normal after I press the radio PTT switch for
> several times.
> I do have this problem for some time now (probably over an year)
> and thinking that it could be the AL-1500 open relay, I
> purchased a new relay (a couple of months ago) and
> installed it along with a fast QSK board (one of this Increasing
> Amplifier Relay speed boards by K6XX),
> NEVERTHELESS THE PROBLEM REMAINS.
>
> So, its not the relay.
>
> I don't know if this is a common problem for you and I really
> hope you can help me troubleshoot the problem and fix
> it.
>
> In order for you to better understand the problem here is a
> description of the setup working along with the
> AL-1500:
> Radio: Kenwood TS-870 (driving the AL-1500 with a max of 70
> watt).
> All antennas show a SWR lower that 1:1.5
> All equipments have got a good ground.
>
> Note 1: I noticed that after I installed this fast QSK board by
> K6XX the problem got a bit worst as reception gets lower
> in strenght even when the amp is ON but I'm not transmitting,
> could I be mistaken ?
>
> Note 2: Another thing is that when this happens I tryed to turn the
> amplifier
> completelly off (no power) and the radio reception is still low until I
> press the PTT, then it returns to normal and never happens again
> while I'm using only the radio, if I start using the amp again the problem
> returns.
>
> Looking for your reply.
> Best regards,
>
>
> Jose E. Ribeiro Sa CT1EEB
> http://www.qsl.net/ct1eeb
>
>
>
>
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>
>
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