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Re: [VHFcontesting] Setting up TE RF amp for use with a sequencer.

To: nosigma@aol.com, vhfcontesting@contesting.com
Subject: Re: [VHFcontesting] Setting up TE RF amp for use with a sequencer.
From: John Young via VHFcontesting <vhfcontesting@contesting.com>
Reply-to: nosigma@aol.com
Date: Sun, 15 Dec 2019 23:30:33 +0000 (UTC)
List-post: <mailto:vhfcontesting@contesting.com>
Taking pin 2 to ground turns on the PA with 5 and 6 still internally connected. 
 

However with 5 and 6 internally connected the rf sensing is still enabled which 
defeats part of the purpose of the sequencer.  The amplifier can turn on if RF 
gets to it even if the PTT ground to rf amp lead from the sequencer is not 
grounded.  

I have had my 991A on 6m buzz my 1.25m amp, same thing happened with the W4IY 
Elecraft on 6m in september.  If I had been using a hard keyed pre amp on 1.25m 
it would have been fried.

I opened up the amp and there is no obvious sign of the pin 5-6 internal 
shorting wire.  Maybe you have to cut a trace now?


Calling TE Tomorrow.

73
John
KM4KMU 
On Sunday, December 15, 2019 John Young via VHFcontesting <nosigma@aol.com> 
wrote:

The TE manual gives some simple instruction for hard keying the amplifier but 
out an abundance of caution I want to verify my understanding of them before I 
start cutting wires and adding relays.

The DEMI sequencer gives a sequenced PTT ground to enable the amplifier.  The 
TE  instructions are to cut the internal  shorting wire between pins 5 & 6 and 
then connect the PTT ground to pin 2.

To enable the RF amplifier the TE instructions are:  1) Connect pin 5 & 6 then 
2) connect pin 2 to PTT ground.

My interpretation of these instruction are:
I need to use the PTT ground to close a relay that connects pins 5 & 6 and then 
use an output from this relay to close another relay that connects the PTT 
ground to pin 2 on the amplifier.

Is this correct?
Is there a better way?

73
John
KM4KMU 


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