[Elecraft] KX3 and KPA1500 compatibility

[Jim Brown]

Hi Karl,

I suspect your problem may be the antennas you've tried, which are not 
wonderful for 75/80M. Almost any antenna will receive well if you don't 
have a lot of noise, but transmitting a strong signal needs a better 
one, and well installed.

  How far are you from the nets you're trying to work? How tall was that 
vertical? What model? Most (but not all) verticals need radials to 
transmit a decent signal. A vertical that needs radials is a lousy TX 
antenna without them.

Most end-fed antennas need a counterpoise to transmit well. Did you have 
one?

How high were those other antennas? Horizontal antennas work better if 
they're high. Do you have skyhooks positioned so that you could rig a 
75M dipole (it's roughly 120 ft long)? They're easy to build and should 
be fed with coax. There are shortened dipoles with loading coils that 
can fit between closer supports.

Have you studied the antenna section of the ARRL Handbook,or the ARRL 
Antenna Book?

Most of the antennas you've described probably need a tuner to load 
efficiently. The KPA500 does NOT include a tuner, so the KAT500 would 
likely be needed. The KPA1500 includes an excellent tuner. 2-3W will 
yield 100W on most bands, about twice that for 200-250W. Yes, you can 
certainly daisy-chain the two amps to get legal limit with as little as 
1W from the KX3.

73, Jim K9YC

On 3/6/2023 1:01 PM, Karl W Hubbard via Elecraft wrote:
> I have a KX3 and a KPA100 amplifier but despite various attempts at verticals, end feds, OCFs, and loops, am unable to call anyone, especially on Elecraft 80 m Sunday nets on 3.784 or 3.786. Reception is adequate with most 5/8 or 5/9 and verify against the call- in list. A lot of people seem to get by with a KPA 500 but reception is not as solid as those running the legal limit. My understanding is that the KX3 is compatible with the KPA 500. What about the KPA1500?
> Question: Is it possible / practical/ safe to daisy-chain a KX3 to a KPA100 and drive a KPA1500?