[Hammarlund] Hammarlund Digest, Vol 118, Issue 6

[Richard Knoppow]

----- Original Message ----- 
From: "Dave Sampson" <challanger13041 at yahoo.com>
To: <hammarlund at mailman.qth.net>
Sent: Thursday, November 21, 2013 11:49 AM
Subject: Re: [Hammarlund] Hammarlund Digest, Vol 118, Issue 
6


miles k2cby

the dero 2f looks 100% like a standard sp-600 vlf and has 
all the exact same functions.
it uses all ceramic discs so one can assume that dero took 
standard military issue sp-600 vlf 31's and slapped their 
own front panel on them. there may or may not be some slight 
component variations such as resistor or capacitor values. 
but since only the manual for the standard sp-600 vlf exists 
(unless some lucky ham has one and hasn't spoken up yet) a 
comprehensive comparison would be difficult. the only 
difference I have noticed by looking at pictures of other 
vlf31s is that the dero uses round transformers instead of 
octagonal.
the dero's have engraved front panels that say dero research 
and development model 2f receiver.
and at the bottom center of the front panel there is a 
standard sized metal id tag that repeats the model info + 
contract data and serial number.
I don't have pictures of my set yet but you can see exactly 
what one looks like if you go to
www.eclipseofthechurch.org/w7ekb/glowbugs/BA/SP600vlf31.html

73s
dave

      http://www.w7ekb.com/glowbugs/BA/SP600VLF31.html 
will get you there. It would be interesting to know what the 
small tag says. The panel sure looks like its Hammerlund, 
maybe they were able to buy them without the brand name. 
Note that the chart of fixed crystal frequencies is on the 
other side of the control knobs to clear the handles.  The 
VLF came with the handles stock as did one of the standard 
range models, not sure which one. I have one of those but 
missing the handles.  I think the purpose of the handles is 
mostly so that one can set the receiver on its front for 
maintenance without damaging anything.
     Another company who modified SP-600 receivers is 
Northern Radio in Canada. The modifications were for 
diversity reception very similar to the JX-17 and for RTTY.


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