[TMC] Wanted: Schematic on a modified FFR-2 (R-5007/FRR-502)

Wed Jul 9 21:30:05 EDT 2008

On Jul 9, 2008, at 7:20 PM, WA5CAB at cs.com wrote:

> I was recently contacted by a collector who has what the nameplate  
> says is an
> R-5007/FRR-502.  I have the NAVSHIPS AN/FRR-49(V) manual, a copy of  
> that
> manual, and the original TMC FFR manual that the NAVSHIPS is based on.

Andy Moorer's site has info on the R-5007 at:

http://www.jamminpower.com/main/R5007.jsp

Including the manual and schematic.  These are apparently the FRR-49  
manual and schematic, however.  I did find in my notes the reference  
to the unusual line voltage situation I remember though. Here it is,  
and a mention of other tube lineups:

> Date: Tue, 15 Jun 2004 20:42:30 -0700
> From: telegrapher at att.net
> To: TMC at mailman.qth.net
> Subject: [TMC] R5002 Reciver
>
>
> Last night i pulled what i had thought was my FRR-49(V) out of the  
> rack
> because it sounded terrible.  Audio was quite muffled and distorted.
> Thought there should be a fix for this.
>
> Looking underneath the chassis i saw that i had previously changed  
> out a
> couple of electrolytic caps as a precaution.  Hmmmm.  Voltages  
> appeared
> to be way high.  ALmost 45 volts high on the plates.  Also some AC on
> the chassis.  WEll better dig into the power supply.
>
> Disconnected the 470 pf and .1ufd caps from each side of the line.   
> That
> took care of the high AC leakage.  B+ still way high though.  But, the
> audio seems to sound a little better.  Pull out the manual.  There are
> two schematics in there for the FRR style receiver. In looking at the
> power supply i figured i could move the line side tap on the  
> transformer
> and drop the voltage down that way.  Looking in the manual the
> transformers are different.  The one for the R5007 receiver only has
> either a 100V or 220V tap.  Nothing in between.  Also noticed looking
> under the receiver there seems to be a lack of .01 bypass caps.   
> Wonder
> why?
>
> So what i did for the interim is drop the line voltage down to 100V  
> with
> a variac and then measure the B+.  Aha.  Now its 255V where it  
> should be
> 250 and the regulated B+ is 150 as it should be.  Filaments are 6.0.
> But, now the receiver sounds great.  Have been running it since last
> night and the audio is very good and the AVC seems to be working  
> pretty
> good.  Don't think it was ever great.  Now i can hear the BFO when its
> turned on whether the AVC is on or not.  Before when i turned it on i
> had to really crank back the RF gain.  Not so now.
>
> Quite surprised to see that the schematic for this particular receiver
> shows a line voltage of 100V instead of the normal 110 or 115.   
> However,
> it do run  a lot better on 100VAC.
>
> the transformer in the FRR receiver has multiple taps on the primary
> side and will accommodate i think shows to be 120Vac on the line side.
>
> Just an FYI for those with the R5007/FRR-502 or FRR-49 (V) receivers.
>
> Larry
> W0OGH
>
> From: "Tom Brent" <tgb at telus.net>
> To: <tmc at mailman.qth.net>
> Date: Fri, 4 Feb 2005 22:26:13 -0800
> Subject: [TMC] R5007/FRR-502 Tuning Unit Info
>
> In June of 2004 there was a lengthy discussion on this list  
> regarding a
> "different" tube line-up in these receivers and I described changes  
> to the
> receiver subchassis in my posting a few weeks ago. This was a  
> modification
> to some of the standard units in service with the Royal Canadian Air  
> Force
> and there is a similar story to tell about the tuning units.
>
> TMC manufactured 8 different tuning units to cover the frequency  
> range of 50
> KHz to 32 MHz. With one exception, they all utilized 6AG5 tubes for  
> the HFO
> and both RF amps: TN-5014/FRR-502 (16-32 MHz) substituted a trio of  
> 6AK5's.
> It should also be noted that the 3 lowest frequency units (50-100,  
> 100-200
> and 200-400 KHz) have a 4 position crystal filter. Like the  
> receivers with
> the tube variation, some tuning units employed with the RCAF were  
> modified
> and use a 5842 and 6BZ6 for the first and second RF stage,  
> respectively. If
> you have a tube manual handy, take a look at the specifications for  
> the
> 5842. It is a very high performance tube and explains why additional
> shielding  is installed across the 1st RF amp tube socket in these  
> modified
> units. The 5842 is also treasured by the glass audio crowd and that
> explains, at least in part, why they are so pricey.
> ...

Roy

>  But the
> tube lineups do not match the list that the collector sent me.  And  
> although my
> NAVSHIPS includes changes up through 1969 and some of the changes  
> involve tube
> type changes, none of the revised lists match, either.
>
> Specifically, the following tubes are different:
>
> Tube New   Manual
> V103 6BE6 6AL5
> V104 6FM8 6T8
> V107 7199  6AG5
> V108 NONE 5Y3GT
>
> I didn't take the time to see what the new V104 and 107 are but I'd  
> say it's
> pretty likely that the 6AL5 2nd Detector/AVC tube was converted to a  
> product
> detector.  I told the owner that my first guess was that it was ham  
> hacked but
> he replied that it was too neatly done and that the tube numbers are  
> all
> stamped on the chassis.  But the nameplate wasn't changed.  So I'm  
> mystified.
>
> If any of this jogs anyone's memory cells and/or if anyone has any
> information that would apply to the modified main frame please let  
> me know.
>
> Robert Downs - Houston
> <http://www.wa5cab.com> (Web Store)
> MVPA 9480
> <wa5cab at cs.com> (Primary email)
> <wa5cab at comcast.net> (Backup email)
>
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Roy Morgan
k1lky at earthlink.net
Lovettsville, VA 20180