[Boatanchors] USS Midway notes

[Carl]

>
> ----- Original Message ----- 
> From: <WA5CAB at cs.com>
> To: <greenkeys at mailman.qth.net>;
> <boatanchors at mailman.qth.net>
> Sent: Tuesday, March 01, 2011 1:31 PM
> Subject: Re: [Boatanchors] USS Midway notes
>
>
>> Actually, if it had an RBG-2 nameplate on it, it's part of
>> an RBG-2, not an
>> HQ-anything.  According to NAVSHIPS 900,004, none of the
>> RBG receivers had
>> a crystal filter.  RBG-1 had a CHC-46163 receiver with 25
>> cps power supply.
>> RBG and RBG-2 had a CHC-46140 receiver and were 60 cps.
>> Otherwise the only
>> differences between the three were the two nameplates and
>> the contract
>> numbers.  Besides the receiver, the rest of what made up
>> an RBG-(*) was a shock
>> mount, a loudspeaker, a case of spare parts, and two
>> manuals.
>>
>> I'm pretty sure that Midway never had a RAK-4 aboard
>> (while in commission).
>> She would have commissioned with RBA/B/C, then probably
>> got R-390A's, and
>> then R-1051's.  I served on another carrier commissioned a
>> few months after
>> the Midway and that was the sequence aboard her.  Late
>> WW-II ships didn't
>> generally have the misfortune of getting the AN/SRR-11, 12
>> & 13.  :-)
>>
>> In a message dated 3/1/2011 2:44:24 PM Central Standard
>> Time,
>> rinkies at att.net writes:
>>> I believe the Hammarlund is the HQ120, or 120X (the "X"
>>> had the crystal
>>> filter in it).  One way to tell is to look at the tubes;
>>> the 129 has all
>>> octal, and the 120 has tubes with grid and/or plate caps.
>>>
>>> I have manuals for both that I can copy if you like, and
>>> live in the San
>>> Diego area.
>>>
>>> Ron K2RP
>     The CHC-45140 is shown at:
> http://www.radiomuseum.org/r/hammarl_mf_rbg_2_chc_46140.html
>     It pretty definitely has the crystal filter in it.
> However, if the tube line-up given is correct it is not an
> HQ-120-X but a modified version with single-ended octal
> tubes and somewhat different tubes than were used in the
> later HQ-129-X (6SK7 where the HQ-129-X had 6SS7).
>     There are a couple of clear photos of the front panel
> at:
> http://www.ohio.edu/people/postr/bapix/RBG2.htm
>     Again showing the crystal filter.
>     While Hammarlund evidently made a version of the HQ-120
> without the filter I have never see one. The Hammarlund
> crystal filter was patented by them and was first introduced
> in the HQ-120-X, being made available for the Super-Pro
> after that. The Hammarlund xtal filter was excellent
> overcoming the defects of the original Lamb circuit as used
> by National and Hallicrafters (and others). This is the same
> circuit later used by Collins, TMC, etc in their receivers.
>     RE 25hz power. The military version of the Super-Pro
> was avaiable with a 25hz supply. The difference is in the
> power transformer and chokes, they will run fine on 60hz
> where a 60hz transformer will overheat badly on 25hz power.
> 25hz was mostly used for large industrial motors of the sort
> used on some electric railways and manuacturing plants. In a
> few places home current was also 25hz. I remember this from
> visiting the Canadian side of Niagra Falls with my parents,
> perhaps in the late 1940's. The local current was 25hz
> making lights flicker quite noticably.
>
>
> --
> Richard Knoppow
> Los Angeles
> WB6KBL
> dickburk at ix.netcom.com
>

Ive never seen a RBG without the xtal filter and that includes the one Im 
looking at.

I already stated earlier that it was a cross between the 120 and 129. That 
was a demand of the Navy that it have single ended tubes and the repaneled 
and repackaged 1946 clone was the 129X. I still prefer the 120/RBG meter.

Carl
KM1H