[Milsurplus] Question ( RBS; submarine )

[Bill Cromwell]

Hi Nick,

There isn't any doubt the fears were real. Whether or not they were well 
founded or how well founded is the mystery, My limited experience along 
with lack of hard citations tells me that df'ing receiver oscillators 
(at microwatt or even picowatt levels) is most unlikely. I have not had 
access to all the regens that have been built and used and it is 
possible some of them on the worst of days may have been a beacon for a 
submarine to find a target. The engineers seeing the 'possibility' 
worked to reduce the risk. That is what I think you are saying and I 
agree. Maybe I will try to better evaluate the bits and pieces that 
comprise the possible threat. I think that means I will be building some 
regens and that will be fine with me. I have reports that regen 
detectors (tubes) draw low microamps for plate current and the plate 
voltage is also quite low. I will try to measure that and try to get 
some kind of handle on power output. I don't know if I can measure power 
that low!

Yes, I have been to your web site. Awsome.

73,

Bill  KU8H



On 08/26/2016 01:52 PM, Nick England wrote:
> Hi ray - I appreciate the compliments and your confidence in my web 
> site :-)
> But DF is far from my area of interest or expertise and my
> www.navy-radio.com/rcvrs/d-df.htm 
> <http://www.navy-radio.com/rcvrs/d-df.htm> page is just a catch-all 
> place for info I happen to come across.
>
> For anyone  seriously interested in the topic, check out "Abstracts of 
> the Available Literature on Radio Direction Finding 1899-1965" at
> http://www.dtic.mil/cgi-bin/GetTRDoc?Location=U2&doc=GetTRDoc.pdf&AD=AD0800110 
>
> which has entries for 5,224 articles to keep you entertained....
>
> My point was that NRL etc. were indeed concerned about the possibility 
> of LO detection. When they designed the RAA, RAK, etc. in the 1930's 
> they were worrying about what a very clever adversary *might* be able 
> to do in the next 20 years. Predicting future technology is difficult 
> and assuming the worst case sometimes makes good sense.
>
> From Gebhard's NRL history -
> "... which included the Models RAA, 10 to 1000 kHz (1936), RAK, 15 to 
> 600 kHz (1939), RAL, 300 to 23,000 kHz (1939), and RBA, 15 to 600 kHz 
> (1941). These receivers were NRL concepts. They included the NRL 
> multiplexing technique and the shielding needed to prevent radiation 
> of local-oscillator energy which could cause detection by an enemy 
> through interception."
>
> I'm just pushing back against what sometimes seems to be a narrative 
> that this was all just a foolish concern and panicked over-reaction by 
> ignorant engineers. It wasn't. Just because you are paranoid doesn't 
> mean they aren't out to get you.
>
> You can't judge what might have happened, by what did happen - without 
> Enigma decrypts, jeep carriers, centimetric radar, etc. maybe more 
> effort would have been put into super-sensitive DF. I certainly don't 
> know.
>
> Cheers,
> Nick England K4NYW
> www.navy-radio.com <http://www.navy-radio.com>
>
> On Fri, Aug 26, 2016 at 12:04 PM, Ray Fantini <RAFANTINI at salisbury.edu 
> <mailto:RAFANTINI at salisbury.edu>> wrote:
>
>     The base of my argument is your web site.  I am not an expert on
>     history or procurement but simply look at the listings,
>     publications and items on line and seeing what’s listed on your
>     web site (http://www.virhistory.com/navy/rcvrs/d-df.htm
>     <http://www.virhistory.com/navy/rcvrs/d-df.htm> ).  What I
>     consider to be the premier web page for US Navy communications and
>     looking at the DAK, DAQ and the shore base DAB don’t see anything
>     up to that challenge.
>
>     If it existed I would think it would be evident in some
>     publication and on your web site.
>
>     Ray F/KA3EKH
>
>
>
> ______________________________________________________________
> Milsurplus mailing list
> Home: http://mailman.qth.net/mailman/listinfo/milsurplus
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Milsurplus at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

-- 
bark less - wag more