[Elecraft] KX3 Computer Interface for digital modes

[Jim Brown]

On 7/28/2012 9:36 AM, Barry LaZar wrote:
> The real issue is amplifier turn on timing.

And the switching of relays for mast-mounted  preamps used in serious 
VHF/UHF stations.

>   As I don't use an
> amplifier as QRO to me is a 100 Watts. I can't address the issue from
> experience. However, I suspect that there is an easy fix since all high
> power users face the same issue, particularly on CW.

But it is NOT an issue for ALL those who use power amps, it is an issue 
for those who use badly engineered power amps with slow relays!  It is 
NOT an issue for my me with my good quality Ten Tec amps, designed c.a. 
1980, which use good vacuum relays, nor with my Elecraft amp, nor, I 
suspect, is it an issue with most Alpha and ACOM products.

The problem is with CHEAP amps -- ever look inside an Ameritron?  -- and 
with home builders playing it CHEAP.  Example:  I recently posted asking 
about build quality of relay switching systems for antennas, and more 
than half of the replys included phrases like "you can use so and so's 
much CHEAPER relays"  and "so and so's system is much cheaper." Mom and 
Dad were both accountants, but they also taught me the difference 
between quality and junk, and when it was worth spending ENOUGH to do it 
rignt.

Now, the nature of some relays is such that fast switching is not 
consistent with good RF performance, and I suspect that the high quality 
coax relays that Lance and others are talking about to switch preamps 
and to switch 2M and higher power amps are inherently not that fast.  
But for conventional ham power amps at HF, decent relays ARE fast enough 
to switch with the delay times provided by rigs like the K3 and 
FT1000-series.

73, Jim K9YC