Recently I had an Omni 6+ in my shack for almost a whole month and ran
extensive comparisons between it and my "good old" Drake R4C. While the
transmitter in the Omni 6+ is by far better, except for power, there was
no significant difference between the receivers. I could not say that
one was better than the other. I was always looking for the very
marginal signals - weak ones that were just barely readable, and those
signals were readable about the same on either receiver. Sometimes when
I thought one receiver may be a bit better, I switched (instantaneously)
finding that it was most likely just a momentary QSB, etc. Also, in
those cases where I thought that one might be a bit better, it was never
consistent - sometimes it was the Omni and other times it was the
Drake. So, since the Omni 6+ is said to have one of the best receivers
currently available, my conclusion is that the Drake R4C is right up
there with the best of them!.
Regarding the Omni 6+, it was borrowed from my good friend, 4X1FC. I
should include here the description of his filters - I'm sorry and
apologize for not doing that. I can say that Dani is very keen on CW
operation (he only operates CW), and I know that in principle, he
purchased his Omni 6+ with the narrowest filters available (and that is
where I made the comparison - using his narrowest filters). I also used
the internal DSP in the Omni while making these comparisons. In order
to be fair to the Omni, I used it with the same analog audio filter that
I used on my Drake R4C. This is an 8 pole, 90 Hz Bandwidth, 700 Hz
center frequency homebrew design.
My Drake R4C has the narrow Sherwood first IF filter, and the 250 Hz
second IF filter. The second IF filter is an excellent Japanese made
filter that was replaced by Drake when the original one had problems.
I've also modified the detector by replacing the Germanium diodes with
Hot Carrier diodes. Another improvement is a dual-gate MOS Fet
Preselector that includes a bandpass filter for 160M and 20 dB of gain.
Another addition with the Drake R4C is the Timewave DSP-59+ outboard DSP
unit that I used with the bandwidth set at 50 Hz for the checks. I
should add, that my analog filter was still used, even though I'm using
a somewhat narrower Timewave DSP - something that I do to clean up the
audio because the Timewave audio output sounds tinny & distorted, and
that is completely cleaned up by my analog filter.
I would really like to add a modern radio to my station to replace both
the aging Drake Line which (because of "too many knobs" and concern
over replacement parts, especially tubes) and my little Kenwood TS-430S.
It's been suggested to me that the Omni 6+, the Yaesu 1000 MP, or the
Icom 775 would be the best candidates. The 1000MP power is a bit low
form my amplifier. Although this is not a problem (at 200 W.) for the
Icom 775, I've not seen anything concerning its receiver performance. I
would appreciate receiving comments, especially about the Icom 775.
73,
Riki, 4X4NJ
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