No, there is no way for it to enable full break-in on an amp which was not
designed for full break-in.
It does enable the Ten-Tec full QSK transceiver (like the Eagle) to operate
with non-QSK amplifiers, like your FL-2100B or most any amplifier, without
burning relay contacts. This is very important.
THE "DELAY" PROBLEM ADDRESSED HERE IS THE DELAY IN SWITCHING THE AMPLIFIER'S
T/R RELAY FROM TX BACK TO RX.
Older mechanical relays were slow in switching.
Let's say the switching time is 20ms.
Ten-Tec transceivers have a built in delay from the time a dit is keyed
until the time the RF is actually transmitted.
I don't recall the length off hand, but let's just say it is about 20ms.
If the amplifier's relay gets the signal to key its relay 20ms before the RF
comes, it will be OK.
So initially keying the amp has not been a problem with modern transceivers.
In fact the Eagle with its built in delay accomplishes this with most older
transceivers - but this is only HALF of the problem.
The other half of the problem is with QSK where the transceiver's relay
keying signal to the amp follows the actual keying of the dits and dahs
(albeit with 20ms delay), where as soon as the dit or dah is finished, the
relay keying signal is removed and the amp's relay starts to return to RX
position. THIS IS WHERE THE TROUBLE IS.
If the next dit comes, just as the amp's relay is moving towards the RX
position, then the amp's relay actually needs 40ms until it can safely
accept power again - 20ms to complete the switch to RX, then 20ms to execute
the next switch back to TX. The transceiver only delays the RF 20ms, so the
RF hits the amp 20ms too soon, and can cause the relay contact to arc.
Eventually the arcing causes a build-up of carbon and the relay no long
makes a clean contact. The first indication of this is you notice that in
receive mode, signals are very weak. Once that happens, you have to get out
your relay burnishing tool and clean the relay contacts. Then it works OK
again, for a while. Then you clean again. The interval between cleanings
keeps getting shorter and shorter.
So, the new Model 318 has provisioned for this by enabling the operator to
insert a delay for switching back to receive. I usually run my delay such
that it only switches back to receive during the pause between words, but
not the pause between dits and dahs of the individual characters. This
virtually eliminates the problem. This is what my own home-brew device
To FULLY illuminate the possibility of ever having arcing, you would have to
add a little more intelligence to the circuit to detect if the amp's relay
is in process of switching back to RX, and if it is, it adds additional
delay before sending the TX-Enable signal back to the transceiver. Thus the
amp never receives RF before it's ready. I don't know if the Model 318 does
this or not - I haven't seen the schematic; I hope it does.
I CONGRATULATE TEN-TEC FOR FINALLY BUILDING THE BOX I HAVE BEEN LOOKING FOR,
FOR 30 YEARS!
Now I can retire my ugly home-brew, bread-boarded QSK box.
PS - I do not have any inside information on this product. I am making a
big assumption here that Ten-Tec built its Key Interface like I built mine,
33 years ago.
From: firstname.lastname@example.org [mailto:email@example.com]
On Behalf Of Gary Winkelman
Sent: Wednesday, February 01, 2012 1:27 AM
Subject: [TenTec] Model 318 Amplifier Key Interface
I'm a little confused by the following statement. Does this mean that I
will be able to use my Omni VI+ running *full break-in* with my Yaesu
FL-2100B? I'm using an interface between them now that has no delay
The 318 will allow you to dial in a delay when you connect older linear
amplifiers to your transceiver. *This will be**
**useful if the amplifier is not designed for full break-in*. An excellent
add-on for Eagle users who want to adjust the transmitted output to work
older amplifiers. Adaptable to almost any transceiver.
73, Gary N2UM
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