Help with K3 & THP amp

[dlrwild1]

I finally hooked-up my K3/100 to my THP HL-1.5KFX amp. I bought a special cable from Array Solutions that provides band data and ALC from K3 to amp. I thought that this cable would also provide relay information also, but it did not. I provided a cable labled “relay” on the amp and “Key Out” on the K3. I now have the K3 keying the amp. With around 45 to 50 watts drive from the K3, I am getting about 700 watts output from the THP amp. DO I NEED to also go in to the “config menu” to set any settings for the K3 to properly adjust any relay delay, voltage keying settings etc.

Previously I used this same set-up with my IC-756PRO2. The THP amp has a variable pot on the rear panel to adjust and set ALC voltage or relay voltage? for various radios. I don’t think that I need to readjust this with the K3, but not sure. I don’t want to damage the relays in either the K3 or THP amp. Has anyone on this Reflector used a K3 with the HL-1.5KFX amp? Please contact Bob, K3SRO at [hidden email]

Thanks
Bob K3SRO
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[Jim Brown-10]

On Mon,12/7/2015 7:51 AM, [hidden email] wrote:
> Previously I used this same set-up with my IC-756PRO2. The THP amp has a variable pot on the rear panel to adjust and set ALC voltage or relay voltage? for various radios. I don’t think that I need to readjust this with the K3, but not sure. I don’t want to damage the relays in either the K3 or THP amp.

I don't know this amplifier, but in general, it is VERY bad practice to
use AGC from the amp to set drive power from a rig. Doing so usually
results in bad splatter and key clicks. As long ago as the early 1980s,
mfrs of decent power amps (in this case, Ten Tec) were telling customers
(in the user manual) to NOT use AGC to set drive power.

The K3 is very well behaved as an exciter for power amps, so the right
way to set drive power is to use the Power Out knob on the K3. I've
never done it any other way, including with a TS850, FT1000MP, and a
K2/100.

The ONLY good use of AGC between a power amp and a rig is to protect the
amp if something in the antenna circuit fails. To do that, hook up the
AGC and carefully set it so that it does not reduce drive power in
normal operation at the highest power at which you operate.

FWIW -- I have NEVER used AGC between an amp and a rig. My amps are a
KPA500 and Ten Tec 425s (legal limit tubes, a pair of 3CX800A7s).

73, Jim K9YC
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