[Premium-Rx] R1451A

[Michael O'Beirne]

Dear Clemens

Many thanks for your interesting contribution.

I made a boob relying on my memory.  The similar receiver was Telefunken's 
e863 not the e893 (silly me).  The version marketed a few years ago by 
Singer of Aachen was the submarine version in a waterproof cabinet with 
internal anti-condensation heaters.  I know a few older subs and don't 
recommend them much for comfort or dryness.

I can well understand the need for compactness for an airborne EW receiver. 
Don't fancy many R390s could be carried in the EW aircraft of those days:-).

Presumably the aeroplane would fly near the area of interest but well out of 
ground fire.

I could find nothing on Water Boy 1 on the Net.  Perhaps others can 
contribute.

I doubt if the R1451A would be of application to radar since radar 
frequencies are so very much higher.

The VLF version immediately suggested submarine activity since VLF will 
penetrate sea water effectively.  I don't think anyone else (other than the 
standard time and frequency signals) use VLF.  Most readers will recall the 
warbles of Criggon on 16kHz and now Anthorn on around 19 kHz.

73s
Michael
G8MOB

----- Original Message ----- 
From: "Clemens Ostergaard" <clemenso at gmail.com>
To: "Michael O'Beirne" <michaelob666 at ntlworld.com>
Cc: "PREMIUM-RX" <premium-rx at mailman.qth.net>
Sent: Tuesday, January 01, 2013 4:37 PM
Subject: Re: [Premium-Rx] R1451A


> Michael, there will be real experts on the list, but until they chime in: 
> I
> believe the receiver, which contains lots of CEI modules, was used in
> airplanes too. During the Vietnam war, the system called Waterboy, a 
> number
> of ground controlled interception sites of the Tactical Air Comman,
> directed fighter planes (in a system originally developed in WW2 Britain).
> This receiver was employed in that connection. Also sometimes referred to
> as a countermeasures receiver (?) perhaps in connection with radar.
>
> It certainly also looks as if it might have been employed in small
> submarines or other craft.
>
> And Happy New year,
>
> Clemens
>
> Aarhus, Denmark
>
> On Tue, Jan 1, 2013 at 12:41 PM, Michael O'Beirne 
> <michaelob666 at ntlworld.com
>> wrote:
>
>> Dear Bill
>>
>> I have looked at the only reference on the net to this set.  A distinct
>> physical resemblance to the Telefunken e893 submarine radio.
>>
>> What was of concern was the 40dB aerial attenuator switch.  Such high
>> attenuation inevitably suggests that the signal handling range was 
>> limited
>> - as one expects with early transistorised receivers.
>>
>> Do you know which parts of the USN used it?  The compact size suggests
>> perhaps for submarines or small warships, given that the large warships
>> were happy to accommodate a battery of big heavy R390As.
>>
>> 73s
>> Michael
>> G8MOB
>>
>> ----- Original Message ----- From: "Bill Tweedie" <
>> bill.tweedie at bigpond.com>
>> To: <Premium-Rx at mailman.qth.net>
>> Sent: Tuesday, January 01, 2013 3:18 AM
>> Subject: [Premium-Rx] R1451A
>>
>>
>>
>>  Hi All
>>> For those who are interested-
>>> This set appears to differ somewhat from the VLF version.
>>> Single conversion fron 0.5 MHz to 8 MHz with 455 KHz IF with filters 
>>> from
>>> 0.1KHZ TO 16 KHZ.
>>> Double conversion from 8 MHz to 32 MHz. First IF is 3.455MHz ( incl a
>>> 'roofing filter' at 3.455MHz)
>>> then 455 KHz through 455KHz filters to selectable AM and product
>>> detectors.
>>> Has an ISB facility with two mechanical filters, one for each sideband 
>>> in
>>> addition to the above filters.
>>> Has a fixed 455KHz BFO plus a variable facility from -8 KHz to +8 KHz.
>>> FET front end with two RF stages & attenuator.  Extensive shielding
>>> section by section.
>>> It is likely that oscillator radiation was minimal fro obvious reasons.
>>> AGC & manual controls. Construction is a work of art.  Circuit boards 
>>> are
>>> Would have cost a fortune to produce in the 1960s.
>>> Bill
>>>
>>
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>