[Premium-Rx] WJ-8711A or WJ-8712P

[Michael O'Beirne]

Dear Ben

Thanks for the mail and the Sherwood link.  I agree it would be wonderful if 
Robert could add the lovely radios we like to his table, but how is the poor 
chap going to get hold of the rare and pristine from WJ and the European lot 
from Telefunken, Siemens, Thomson-CSF, Hagganuk, SAIT, Racal, Redifon, 
Marconi and Plessey etc?  Perhaps some group members will loan theirs to 
him?

The batting order of Robert's table is determined by the narrow band dynamic 
range and it is interesting to see how the ancient R4C with the expensive 
Sherwood mods still does very well, but it's not a lot of use for general 
coverage beyond the limited bands provided and I cannot think of kind words 
to absolve the crunchy tuning of its nylon gears.

In terms of synthesiser purity the HF1000 scores badly.  That said, so does 
the KWM380 yet many users says the effect is not readily noticable on the 
air.  So I ask philosophically how many of these parameters are very 
important?  The answer is surely "it all depends".  For me operator 
usability is the most important followed by the quality of the sound that 
the radio delivers to my hifi cans or hifi speaker.  It would be helpful if 
Robert would add a few more columns which reflect these important 
parameters, particularly in-band intermodulation and detector and AF amp 
distortion.   These are included in Peter Hart's reviews in RadCom.

For others who listen to the noisy tropical bands, other parameters are more 
important, and CW users will want something else, for example superb AGC 
with zero popping as exemplified by the R&S EK0-70 and the RA1792.  The data 
guys will want minimal in-band distortion and phase-compensated crystal 
filters, typically on the Marconi H2540 and H2541 and the DSP filters of the 
8711.  You cannot satisfy everyone!

The widest published comparison of professional kit that I know of was an 
article and massive table printed in Marconi's house journal "Point-to-Point 
Communication" in January 1974.  It got them into big trouble when Racal 
injuncted the entire issue for product defamation.  Read my long piece in 
Radio Bygones issue 87 for February / March 2004.  The original article is 
still available in the copyright copy deposited in the British Library in 
London and I think there is one at the Science Museum library.  The 
methodology makes for fascinating reading.

73s
Michael
G8MOB


----- Original Message ----- 
From: "benwallace @dslextreme.com" <benwallace at dslextreme.com>
To: "PREMIUM-RX" <premium-rx at mailman.qth.net>
Sent: Saturday, January 05, 2013 4:38 PM
Subject: Re: [Premium-Rx] WJ-8711A or WJ-8712P


> Wouldn't it be interesting if someone such as Rob Sherwood could test some
> of the premium receivers and document their performance?
> Here's a link to his Receiver Test Data: 
> http://www.sherweng.com/table.html
>
> Scroll down and you'll see how the HF-1000 performed.
>
> Ben Wallace
> WB8HUR