Jim I listened to the same groups as you yesterday on an SX 117. I did not
have any trouble copying each of the groups. While some of the aflack noise
could be heard, it did not affect my copy that much. I turned on the HRO 60
with the D coil in the General Coverage mode and was able to copy very well
with it.
I am about 500 miles North of you and was using a dipole and an inverted L
on both receivers. I didn't try the NC 183D but it tends to be almost as
selective as the HRO. I also have an R 75 and I really don't see that much
of an improvement in reception. I do not have all the filters in it as you
do, but the S- AM mode does not help that much. Also my R 75 does not have
any modifications.
73 Jim
W5JO
Hi All,
Yesterday morning on 75 meters we had at least 3 AM QSO's going on
simultaniously. It was glorious! I heard QSO's on 3880, 85, and 90. At the
same time there were SSB groups on 3878, and 3894.
At my QTH (central Texas) with my equipment, my SP-600 was useless. Yes I
could use the 3Kc IF bandpass position, and tune off center to favor one
sideband or another. As soon as the audio midrange would brighten up I'd
hear QRM from an adjacent channel. Switching in the 8kc position resulted
in
a maddening array of signals besides the one I was wanting to hear.
Then I switched to my Icom R-75 with 3 mechanical filters that are about
2.4, 3.5 and 6 khz in bandwidth. I could hear all 3 QSO's Q5 in AM with
the
3.5 Khz filter, but it was no fun because the upper mids, and all highs
were
gone. Then tune off 1 Khz, and much better or turn on the synchronous
detector, offset the passband tuning 2.4 khz (or 3.5), select the 2.4
filter
(or 3.5), and golly Gee! Nice sounding AM on all 3 QSO's so long as you
pick
the better sideband.
As the morning went on the QRM went away, and all we had was the traders
net
on 3890. Now the SP-600 ruled until the signals started dropping from
daytime propagation kicking in. Now I was experiencing QSB, selective
sideband fading, and occasional impulse line noise. Switch back to the
R-75,
turn on the noise blanker, and synchronous detector. Back to Q5 again!!
This is not a tube versus solid state issue. Chuck Wa0zhh has a all tube
HB
receiver that has most of the modern features, and his receiver can
probably
blow the doors off my R-75. Chuck likes old style octal tubes too like the
6L7 in his noise blanker circuit.
So how would a R-390 have done yesterday, or a NC-183D, Bretts HB tube
receiver, or one of Darrel's HB tube receivers?? Just curious.
Jim
JKO
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