[CW] New RadioTelegraph Operator License

[Richard Knoppow]

----- Original Message ----- 
From: <sbjohnston at aol.com>
To: <cw at mailman.qth.net>
Sent: Tuesday, May 21, 2013 5:10 PM
Subject: Re: [CW] New RadioTelegraph Operator License



The receiver is a Chinese military 222-1 HF receiver.
I wrote an article about it for QST - it is posted on my 
website at ...

http://www.wd8das.net/222-1.pdf

It is a sort of hybrid of many of the late American 
communications receiver designs and performs very well.
I do wish it went lower in frequency coverage, though... 
Many military and
government receivers seem to stop at the top of the AM 
broadcast band - I think
it was an attempt to keep operators who were supposed to be 
monitoring frequency
xxxx from instead listening to their favorite broadcast 
station.

Here's a higher-resolution photo of the receiver...

http://www.wd8das.net/222-1hires.jpg

And here's the schematic...

http://www.wd8das.net/222-1schem.pdf


Steve

     Thank you.  Its not familiar but is very elegant 
looking.  I don't think the limit on broadcast band coverage 
was so much to prevent operators from listening as it was to 
simplify the receivers.  Also it allows the use of a higher 
IF desired.  The curious thing is that historically, what is 
now the MW broadcast band was the most popular band for 
naval communications.  The Navy continued to operated in the 
band after broadcasting was commercialized at the end of 
1920 but I think vacated it fairly soon afterward.


--
Richard Knoppow
Los Angeles
WB6KBL
dickburk at ix.netcom.com