Hi Dave,
First: Yes, the amp likes to have at least 6' of cable between it and the
rig. I've found that using a shorter cable leads to higher input SWR on some
of the bands. You can use a longer cable, but may need to tweak the length
for optimum input SWR on all bands.
You can connect the FT-1000D TX GND jack directly to the 87A RELAY jack. The
PIN diode switching in the 87A is lightning fast, and the FT-1000D has
several milliseconds of delay between key down (amp relay activated) and RF
output. So you don't have to worry about timing issues, and you don't have
to use a keying loop like you would with an amp that uses a mechanical T/R
relay (even a vacuum relay.) The factory default for the FT-1000D is for the
TX GND relay to be disabled to avoid clacking of the relay when it's not
used. If you don't hear the relay when you transmit, you'll have to turn it
on. To do so, remove the top cover and move switch S1002 to the ON position
(see page 9 of the manual for a photo of the switch location.)
If you run QSK, and/or don't like the clacking of the FT-1000D's amp keying
relay, you can used the solid-state amp keying loop available on the Band
Data jack. You need a DIN connector that will fit the Band Data jack. When
that connector is inserted, the keying loop is automatically activated. Use
shielded wire to connect LINEAR (pin 8) and GND (pin 3) on the Band Data
jack to the 87A relay in jack. You must ground TX GND (pin 2) for this to
work. You can ground it to pin 3. TX GND is intended for amps that use a
keying loop, but do not attempt to connect TX GND to the 87A's KEY OUT jack
-- i.e., don't use the keying loop. The 87A keying loop doesn't work
properly and it's not necessary with the fast PIN diode switching. Even with
the solid state T/R switching in the FT-1000D, there's still plenty of delay
between keying the amp and the start of RF.
Except for TX GND, be very careful not to short any of the pins on the Band
Data jack, especially +13V (pin 1.) You could damage something.
Also, if you use the solid-state keying, you should switch off the linear
relay to avoid the clacking noise and unecessary wear (see above.)
All of this is documented in the manual, though you may have to hunt around
for it.
Hope this helps.
73, Dick WC1M
> -----Original Message-----
> From: David J Windisch [mailto:davidjw@cinci.rr.com]
> Sent: Saturday, November 22, 2008 4:48 PM
> To: Amps@contesting.com
> Subject: [Amps] QSK connections using FT-1000D driving Alpha 87A
>
> Need help, please, cuz I'm used to Ten-Tec Titanic's method of keying
> the amp switching circuitry, which in turn keys the xcvr.
>
> Btw, does the amp truly need 6' of cable 'tween it and the xcvr?
>
> Tia & 73
> Dave W8FGX
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