[Milsurplus] Doubting the Foxhole Radio, conclusions

[Al Klase]

Gentlemen,

We also have to consider the situation before the low-radiation specs 
were implemented.  Merchant ships were carrying regenerative receivers, 
some without RF stages, standing watch on 500KC.

I own a working IP-501.  These were still in use in the 1930's, and I 
understand they continued to be used on the Great Lakes throughout the 
war years.  A few years ago I tuned it up on 500 into a 65-foot antenna, 
oscillating so it would hear CW.  I arranged a square-wave generator and 
a relay to key the antenna terminal to ground at a 1-Hz rate.  I could 
here the thing a kilometer away by just holding the Yacht Boy 400 out 
the car window.   I wouldn't want to try sneaking past a U-boat like that.

Al

On 8/3/2012 11:18 AM, J. Forster wrote:
> Without active multicouplers and coax receiver inputs, the reduction of
> interferance with other gear does make some sense. And, not only for ships
> but for bases with many receivers.
>
> Certainly more than the LO DFing story, IMO.
>
> -John
>
> ============
>
>
>
>> And oh yes, the other reason I have seen for reducing LO radiation is to
>> prevent interference with other receivers aboard ship. This sounds quite
>> plausible for Navy gear where there might be multiple rcvrs on the same
>> band operating in close proximity shipboard or at intercept sites
>> (sometimes sharing a common antenna with just a 600 ohm isolating
>> resistor). The RAO-2, for example, evidently had an extra RF stage added
>> for this reason. But it doesn't seem as likely a reason for modifying
>> Merchant Marine morale radios.
>> http://www.radioblvd.com/WWII-PostWar%20Hamgear.htm
>>
>> Nick K4NYW
>>
>> On Fri, Aug 3, 2012 at 10:49 AM, Nick England<navy.radio at gmail.com>
>> wrote:
>>
>>> It's still not clear to me how much of a danger DF'ing the LO actually
>>> was, but it is certainly true that receivers were modified to reduce LO
>>> radiation. Evidently these modified rcvrs were given production and
>>> procurement priority and widely used, so the purpose couldn't have been
>>> to
>>> prevent anyone from getting information via other than official
>>> channels.They were called morale receivers for a reason.
>>> http://www.imradioha.org/images/Gear/Scott_SLR-12-A_1942_Ad.gif
>>>
>>> Another "cover-up" explanation I have heard is that the reduced
>>> radiation
>>> was a way of explaining the reduction of U-boat success rates when the
>>> real
>>> reason was Bletchley Park's reading the Enigma traffic. But the timing
>>> on
>>> that doesn't see all that good either.
>>>
>>> The true story can be found in that giant warehouse seen in the Indiana
>>> Jones movies...
>>>
>>> Nick K4NYW
>>> www.navy-radio.com
>>>
>>> On Fri, Aug 3, 2012 at 9:14 AM, J. Forster<jfor at quikus.com>  wrote:
>>>
>>>> The issue of DFing LOs was, IMO, a canard. A crystal set could not be
>>>>
>>>> detected by any means, of course.
>>>>
>>>> While it is theoretically possible that LO leakage could be detected at
>>>> short range, it is very doubtful that it would be of any real use to
>>>> the
>>>> enemy.
>>>>
>>>> After 70 years, the original purpose of such things is highly suspect.
>>>>
>>>> IMO, it was much more likely a cover story to prevent the troops
>>>> getting
>>>> information via other than official channels.
>>>>
>>>> Disinformation was an integral part of war. Just look at the efforts to
>>>> spoof the D-Day location.
>>>>
>>>> Politicians are trying to do exactly the same thing today, thankfully
>>>> with
>>>> only limited success.
>>>>
>>>> YMMV,
>>>>
>>>> -John
>>>>
>>>> ============
>>>>
>>>>
>
> ______________________________________________________________
> 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
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2012.0.2196 / Virus Database: 2437/5174 - Release Date: 08/03/12

-- 
Al Klase - N3FRQ
Jersey City, NJ
http://www.skywaves.ar88.net/