[Amps] Keying Kenwood TL922 with Yaesu FT1000D (both old guys)

Bryan Swadener bswadener at yahoo.com
Sat Oct 19 15:17:23 EDT 2013


Jean,
 
The TL922 T/R control has the same problem that the
Heathkit SB-220 has... whatever drives the "RL CONT"
input must discharge 0.02 uF (C27 + C61). While the
two relay coils' DC resistance permits only a small
amount of current to flow, the instantaneous
discharge current of C27+C61 results in a HUGE
current spike of several Amperes.  THAT is what
welds tiny 1A driving relay contacts and shorts most
driver transistor junctions.  Rich AG6K has suggested
using a small resistance in series to limit discharge
current.  According to the FT1000 user manual on
page 67, it can be optioned to drive up to
220 VDC @ 300 mA.
 
On the other hand, if you want something that is
FAST (QSK), look at what Jim W7RY offers.
 
vy 73,
Bryan WA7PRC
 
 

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Date: Fri, 18 Oct 2013 23:14:20 +0200
From: Jean ON4AEF 
Subject: [Amps] Keying Kenwood TL922 with Yaesu FT1000D (both old guys)

Hi guys;

Anyone could me put in the right way for next coming contest.
Witch connection plug I best use on the back of the FT1000D for keying this old TL922.
I saw that the Tl922 keying system has been modified so it could be keyed by means of a low power transistor.
The keynig system of the FT1000D could not be damage by this setup !
I useual do not handle with amplifiers in my ham carreer so poor expirience around hi..  

Kindly regards and thanks to all I look forward 

Jean ON4AEF.

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