[R-1051] Obscure Spectrum Generator alignment question: A1L2 - 500kc input peaking

Tue Aug 28 18:51:56 EDT 2012

On 08/28/2012 02:57 PM, David Wise wrote:
>> -----Original Message-----
>> From: r-1051-bounces at mailman.qth.net
>> [mailto:r-1051-bounces at mailman.qth.net] On Behalf Of Dennis McLaughlin
>> Sent: Monday, August 27, 2012 5:38 PM
>> To: r-1051 at mailman.qth.net
>> Subject: Re: [R-1051] Obscure Spectrum Generator alignment
>> question: A1L2 - 500kc input peaking
>>
>> Dave,
>>
>> Could L2 series resonate with C3 and the lump sum value of the Q1
>> trigger amplifier?  C3 looks like it is to big to do this.
>> I checked mine a while ago.  I had 0.6 v p-p at A1J3 and the
>> signal was
>> OK at TP1 so I didn't try to adjust the slug. I will remember the
>> acetone trick.  Good one.  I adjusted C301 in the frequency standard
>> while the radio was fully assembled with the frequency standard cover
>> off.  If I remember right the adjustment was broad and could
>> be adjusted
>> with the standard removed from the radio.  The cable and module
>> capacitance would not detune T302 (500 khz).  Maybe L2 is the same way.
>> The 10 mhz adjustment C307 in the frequency standard is quite
>> sensitive
>> and could easily be misadjusted.  I made that adjustment with
>> the radio
>> fully assembled with the frequency standard cover off.
> I wondered about that, Dennis, but I'm with you; C3 is too big.
> Plus Q1 is unbiased, so C3 will build up a charge and only be
> loaded on the negative peaks.  To L2 it will mostly look like
> C3 (10nF) and R2 (4.7K) in series; no Q to speak of.
> I think that except for the "lucky" ones with the early-type
> frequency standard, we can ignore L2.
>
> Thanks for the frequency standard tips.  Mine's acceptable, but
> given the happy results so far I'll probably touch it up, just
> because I can.
>
> You made me look up the frequency standard schematic, to see
> which manual you're using.  You're using NAVSHIPS 0967-970-9010,
> the R-1051B manual.  I compared with NAVELEX 0967-LP-970-9010
> (which documents -plain late production), and the A2 multiplier/divider
> boards are *completely different*.  It looks like different
> engineers did them, working to the same spec.  It's great to
> have a variety of resources.  Now I'm curious, which kind do
> I have?  I'll report back another time.
>
> Dave Wise
> SWL in Hillsboro OR
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Dave,

Your right.  L2 just acts as a auto transformer to step up the voltage 
and with the gain of Q1 trigger the multivibrator.  Page 4-62G paragraph 
4-231 of NAVSHIPS 94841(A) gives a description.  NAVELEX 
0967-LP-970-9010 page 4-87, figure 4-32 shows the waveform.

I have 8-1/2 x 11 and 11 x 17 pages printed out of all of the manuals.  
I use a lot of the 11 x 17 block diagrams and schematics out of NAVELEX 
0967-LP-970-9010.

On to the frequency standard where it all the fun begins.

A list of the standards that I have.  Most don't work.  Sorry for the 
bad table.

R-1051 Frequency Standards

                                 FSC   Contract Code?     
ASSY                  MFR        PART NUMBER                REV    
SERIAL NO.    Notes

A70745-001       58189                                              
B        D00803

4013399-0701   6854                                                      
     B-20788         Standard installed when bought.
6625-00-078-4718                                         4013399-0701    
06845                                                       
B-21074          Bad R2 resistor. Cooked.  Needs repaired.
6625-078-4718                                              
4013399-0701    06845        
                                                B-10201          With 
additional voltage regulator.  Needs repaired.
6625-078-4718                                              
4013399-0701    06845        
                                                B-0397           One 
used for testing thermistor
                                          98738                   
01A228203-01    20284    TC939 MODIFIED TO TA973        
112                 R-1051H Style, Under repair
6625-01-055-5294           98738                   01A228203-01    
20284                                              B       
0059                R-1051H Style, Used in radio
6625-01-163-1323 6625  98738                   01A228203-01    20284    
TA973                                 A      2024                Last 
one bought on Ebay,

                                           10MHz output low.

                                           Needs adjusted. R-1051H Style

The A70745-001 doesn't work.  When it heats up it stops oscillating.
The three of the four 4013399-0701's don't work.  The one that does 
takes a while to stabilize.
All of the 01A228203-01 styles that I have have a A2 board like the 
4013399-0701.  They don't have the LED.  They use a lamp.  The A2 boards 
have minor transistor type and component changes.  The A1 boards are 
almost the same.  The additional A4 board provides automatic switching 
from an external 5 MHz source to the internal oven 5MHz source.  I use 
the radio with a external Milliren OCXO.  On and always ready to go.

Dennis