We had the same T/R relay noise issue with 9500 and 8406 amps. These are
shared with N4CC at our remote site. Last year, just before
decommissioning gear at the old site, the RF input relay failed on the 8406.
That amp uses a tiny datacom input relay.
In the process of replacing the input relay, inspection of the Gigavac G41C
output relay showed that it is flush-mounted against a PC board. When the
relay activates, mechanical noise is transmitted like a violin string to a
sound board. Fortunately, there's enough PC board space to shock-mount a
GH1/RJ1 type. After mounting the new relay, I used finely-stranded silicon
HV wire, formed in loops for connection to the relay terminals. This
technique minimizes mechanical noise transmission through the wiring.
Unfortunately, adding an identical GH1 to the 8406's input is not so easy.
The area around the datacom relay is densely packed with parts and the relay
uses small PCB pads. The input relay does produce a small amount of noise,
but not nearly as much as the G41C before modification.
Relay noise transmission in the 9500 is even worse as the images shown in
the prior post show us why. It's doubtful I'll make the change. An
Elecraft KPA1500 is on order and will replace both amps. The benefit for
us:
- Fast, PIN Diode T/R switching;
- Distribution of weight; PS will rest on the floor and give us much more
desk space with just one solid-state RF deck;
- One amp instead of two handles 160m-6m;
- Native Ethernet connectivity;
- instant on;
- Almost no power consumption in standby; Today, we leave the amps running
with filaments on, then place in operate mode after remote site log-in is
complete.
Paul, W9AC
-----Original Message-----
From: Amps [mailto:amps-bounces@contesting.com] On Behalf Of Ted Orant
Sent: Thursday, November 23, 2017 12:03 PM
To: amps@contesting.com
Subject: [Amps] 9500 amp.
Sent from my iPad. Eventually r f concepts will be out of business.Prices
are ridiculous.I still own my 9500,I need a blower for this amp they charged
me 250.00 exchange.I paid the price,but will not purchase from them
again.After that I have a Acom 2000.very happy.Tnx for reading. I think
solid state is here to stay.
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