[Elecraft] Field Day Operation

[Steve L]

Yes, as I understood it, the Icom rise time default is a BAD choice, but recent (e.g. IC7300 and others) radios permitted changing this to a better value, although still behind the cleaner output of Elecraft & Kenwood.

The other interesting part of the discussion was the use of “pre distortion”.  Again I read this as a way for the exciting transmitter to compensate for non-linearity (and resulting dirty emissions) introduced by a modern semiconductor based “linear” amplifier (one place where tubes excel).

All new and interesting stuff to me - and apparently the driving force behind the ARRL “Clean Signal Initiative” to both define better standards, then rate transmitters in ARRL testing against these standards.  And of course, encourage/coerce manufacturers to clean up their outputs!

Steve

> On Jul 1, 2023, at 3:33 PM, Jim Brown <jim at audiosystemsgroup.com> wrote:
> 
> On 7/1/2023 10:34 AM, Steve L wrote:
>> The IC7300 was among the better commercial transceivers in terms of spurious emissions, clicks, splatter, etc. It wasn’t at the top of the list (the K3s is however), but was in the “better” category. However, Rob recommended a change in the CW signal rise time to no less than 6 milliseconds - I forget which menu item it was - but he criticized Icom specifically for a default setting that induced key clicks.
> 
> ICOM rigs are NOT among the cleaner ones -- that spot falls to Kenwood, which is second to Elecraft (and, I suspect, Flex 6000 series, which I haven't measured).
> 
> Yes, adjustable rise time is a REALLY bad idea, which K6XX pointed out in 2013, and which I measured on the air for K6XX's talk, in a neighbor's ICOM rig. Slower is better, but Elecraft's is best by far, carefully shaped keying waveform.
> 
> 73, Jim K9YC
>