[Elecraft] Receivers

[George, W5YR]

Jerry, maybe the point here is that the "numbers" while interesting and
usually an accurate reflection of performance are so "good," as are most of
our modern receivers, that it can be difficult to ascertain much if any
practical discernible difference between any two radios, considering the
noise and QRM, etc.

I have conducted many listening tests among my Icom PRO, Kachina 505 and
Icom 765 and usually find that I can hear a weak signal on any one of them
- sensitivity is not an issue with most modern gear.

The difference comes in what the signals sound like and how much junk I
hear in addition to the desired signal. That is the part that most of the
testing misses since it is largely subjective. What I might consider as
unacceptable adjacent channel QRM or key clicks or whatever, you might pay
little attention to and find to be of no consequence. I might find that a
weak SSB signal is easier to copy on my PRO because of the much better
audio and filters while someone else might care less about what it sounds
like as long as they are able to make out the words.

I have used most of the radios that have been around since 1945 starting
with a little Hallicrafters S-20R. At the time, I usually found each
adequate for the job at hand and the overall conditions at the time. I do
know that when I got my National HRO-5TA1 in 1947 - my first really
top-tier radio - I did notice quite an improvement over the previous ones I
had used. But as good as that radio was at the time, it would be left in
the dust compared to the performance - not features, but actual r-f and a-f
performance - of my modern radios, especially the PRO.

I think that a major difference between your 1951 radio and my 1947 HRO and
today's receivers is that sensitivity is no longer an issue of any
importance. Back in those days, National used two high-gain r-f stages
before the mixer in order to obtain a microvolt or so of sensitivity. What
they also got was a front end that would crumble at the least sign of an
adjacent strong signal. But since all the radios of that era did the same,
we were blissfully unaware that things could have been better so we judged
our receivers on how weak a signal we could hear. Today, it is little
problem to have a tiny fraction of a microvolt signal be detectable above
the noise floor. That accomplishment together with almost bullet-proof
front ends and extreme IF selectivity capabilities make our modern radios
so good that it almost takes a set of objective measurements to
discriminate among them.

Still, as some have reported, many have assessed their radios in comparison
with others using nothing more than an antenna switch. I can't argue with
them although my recent experience is that among my three fairly modern
radios, there isn't a nickles's worth of difference in their relative
weak-signal gathering abilities. But, what they can do with that weak
signal is what puts them in rank order, with the PRO heading the list by a
long way.

And, Jerry, you are not the only one whose ears are losing those highs,
more of them every day!   <:}

73/72/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 I-LINK 11735
Icom IC-756PRO #02121  Kachina 505 DSP  #91900556  Icom IC-765 #02437


"Jerry W. O'Dell" wrote:
> 
> It was interesting to hear the comments on my question (misspelled, by the
> way),
> about receiver sensitivity.
> 
> The most common answer was that somehow, someway folks ears are better
> than the test gear.
> 
> I absolutely guarantee that mine aren't. I don't see one whit difference in
> sensitivity in modern rigs over my 1951 rig, to my ears. Bet the meters would
> find it.
> 
> Reminds me of the monster cable zealots, but I don't want to start a flame war.
> 
> I suppose I should never have been trained as a scientist.
> 
> 73 jerry w8gnd