In a message dated 98-02-09 17:01:03 EST, K6SE writes:
<< Maybe ARRL should report "clickability" in their product reviews, rather
than just displaying the waveform (is anyone from ARRL listening?).>>
It is a shame that so "simple CW" signal generation gets messed up in those
sophisticated computerized rigs. My biggest complaint in that area goes to
inability to lower the CW pitch down to about 200 Hz. Most rigs would go
"down" to about 400 Hz, some stay around 800 Hz.
The problem with initial spikes or clicks on CW is usually aggravated by
turning up drive, that gets TX AGC involved and magnifies the spikes. It helps
to keep the drive set at the point just a hair down from the max drive, when
there is no more increase in power. With transceivers most people don't know
about clicks, and it helps to notify "offenders" about the problem. (Make sure
your NB is OFF!) With sharp CW filters (like 125 Hz) one can really
distinguish or spot wide band clicks.
Fast BK operation and with amplifier also aggravates the problem further.
(Each dit or daaaah becomes first and challenges the TX AGC and switching
circuitry). Overdriving the PA is another "magnifier" of clicks.
I will have a look at some rigs and see if simple remedy is in store. Got
equipment and service manuals, need some free time. Now "souping up" the
IC781, looks promissing. IR filters (2.1, .4, .125) helped quite a bit. Still
want to change RF switching diodes and varactors in oscillators to reduce
phase noise.
One comment on the survey: on 160 m receivers, selectivity plays major
role, especially in the contests. I have found that at the times 125 Hz filter
cuts the band noise down, improving S/N ratio. This in combination with DSP
filtering makes some signals "come out" of noise. Installing better filters is
the single most important modification one can make on any radio. The old 930
with sharp filters can come close or beat much more expensive radios with
"stock" filters.
(Knowitalls at Kenwood refuse any cooperation with us "racing drivers")
de Yuri, K3BU, VE3BMV
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