Pat
Thank you for the great description. A simple variant of what you have done
should suit my needs nicely.
73
John
KM4KMU
Sent from AOL Mobile Mail
On Sunday, November 19, 2017 Pat Patterson <ppattrsn@swbell.net> wrote:
Hi John,
I have a FT991A in my Rover. I don't have preamps (except those built into
"brick" power amps). I use a headset with Yaesu mic connector adapter. PTT on
the front panel jack is broken out by the adapter...1/8" jack for Mic and 1/4"
for PTT . I use a foot switch to key a PTT relay that, through band select
relays, keys band specific T/R switches and AMPs. I have a small fixed delay
from that relay to the PTT lead on the front panel of the FT991A. I have VOX
and CW Break-in disabled. I'm adding bands and preamps so there will be some
form of sequencer in the future.
Best I can tell, the TX INH lead on the FT991A Linear/Tuner DIN jack will
prevent any RF from being made by as long as it is held high (over 5V). So, If
you can provide >5V to TX INH until your Preamp is safely conditioned for
transmitt that should eliminate the possibility of screwing up with VOX or
Break-In on CW....overriding the front panel PTT lead. Here a nice article by
David, VK3HZ, that layouts out a sequencer for use with a Yaesu FT-817 and
transverters/Amps. http://www.vk3hz.net/sequencer/FT817_Sequencer.pdf . I
think all Yaesu rigs that have TX Inhibit leads work the same way.
Enjoyed visiting with you at the Pack Rats conference. Good luck in the
January Test.
73,
Pat, W5VY
From: John Young via VHFcontesting <vhfcontesting@contesting.com>
To: vhfcontesting@contesting.com
Sent: Saturday, November 18, 2017 4:47 PM
Subject: [VHFcontesting] Any one use an FT-991A with a mast mounted pre amp?
I would like to add a 2M mast mounted pre amp to my station. The FT-991A has a
rear jack for tuner and RF power amplifier control. The manual describes each
pins purpose (ex: TX INH, TX GND, GND) but it gives no information on the
function of each pin or more importantly timing information. I would like to
think that I can use these pins with a set of relays to prevent transmission
until the pre amp is taken out of the RF transmit line.
I can not find anything on line after several google search sessions describing
these pins, their affect on the transmitter or showing how anyone else has
used a mast mounted pre amp with the FT-991A (or the FT-991 for that matter).
Any advice on how to proceed would be appreciated.
73
John Young
KM4KMU
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