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[TenTec] Re: TT vs 756PROII

To: <tentec@contesting.com>
Subject: [TenTec] Re: TT vs 756PROII
From: w5yr@att.net (George, W5YR)
Date: Sat, 02 Feb 2002 16:07:42 -0600
Ran some more tests last night using the CW function/mode of MixW 2.02 as a
keyer. It is the only program I could find that has actual "weighting" as
an option.

Default is "0" which does not change the basic weighting of the rig.
Increasing this number - no idea what it measures, but suspect it is just a
relative number - decreases space length or lengthen dots or both - seems
to be the former from looking at the scope. With a setting of 100, the dots
are about 10+ times longer than the spaces.

In any event, a setting of 3 gave the r-f output of the PRO an exact 1:1
dot/space ratio. The evidence was clear from the scope but just perceptible
to the ear on the 765 monitor receiver. I set the PRO keyer to the same
speed as the MixW program with each test and tuned the 765 to the same
offset of 700 Hz. Alternating between holding down the dot paddle and
sending a long sequence of 5's from the keyboard allowed me to see the
difference in spacing clearly and switching from the PRO sidetone output to
the 765 output allowed me to hear the difference.

For casual use, I think that the PRO with 6 to 8 msec rise and fall times
is "close enough" at speeds of 25 wpm and less to be acceptable. But for
higher speeds and the desire to use shorter rise/fall times, the program
keyer should be used. Fortunately this is easily done by wiring a paddle to
the joystick port on the computer so that one has a choice of keyboard
real-time keying, stored macro keying or real-time paddle operation. A very
versatile and capable program.

For non-computer use, the Logikey K3 sounds like the next best solution
with its "K" function. I'll try out both over the next few days and see
which I prefer.

The problem Steve mentions about the overly heavy sidetone keying is a
product of the 10 msec (on my rig) increase in the sidetone elements over
the actual r-f output elements when running QSK. So when the external keyer
forces the spacing to be less, the sidetone dots are relatively much longer
and hence heavier than the transmitted dots.

Back in the 40's I used a war-surplus BC-221 with my homebrew VFO both to
keep me inside the band and to monitor the keying. Looks like I may have to
dig the old 221 out of the closet again just to have a decent keying
monitor! Anybody remember the days when we used audio oscillators that were
keyed by rectified r-f from the antenna to give a sidetone?

72/73/oo, George W5YR - the Yellow Rose of Texas         
Fairview, TX 30 mi NE of Dallas in Collin county EM13qe   
Amateur Radio W5YR, in the 56th year and it just keeps getting better!
QRP-L 1373 NETXQRP 6 SOC 262 COG 8 FPQRP 404 TEN-X 11771
Icom IC-756PRO #02121  Kachina #91900556  IC-765 #02437

All outgoing email virus-checked by Norton Anti-Virus 2002


Steve Ellington wrote:
> 
> You're absolutely right Tom. In fact, when I use an external keyer on the
> 706 while in QSK mode, the keyer's sidetone is unpleasant to listen to
> because the weight has to be so heavy. I suppose keyers need weight controls
> on their sidetones as well as on their output line! With each rig Icom
> introduces, I keep hopeing they will fix this. Does anyone listen? W9UR who
> works for ICOM has complained about this for some time with no progress.
> Once while visiting his QTH, I noticed he was running a TS-570 which has
> pleasant QSK.


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