[time-nuts] Intro & Q: Racal-Dana 1991 or 1992 Counter ?

cfo xnews2 at luna.kyed.com
Thu Jan 19 15:58:25 EST 2012

Hello Nuts

I'm a Danish radio ham , and have recently picked up electronics again.
I'm programming AVR & ARM controllers , and doing some basic electronics 
stuff. I am rusty in analog electronics , and even have to lookup how to 
calculate a base resistor on a bjt. 

I have recently been bitten by the "time-bug" (last summer).

All i wanted was to check/adjust the TCXO on my Phillips PM-6674 freq. 

So i got one of the adjustable ?-20Mhz FEI-5080A from fluke.l
But was the RB correct ?

So i got a TBolt , has some troubles getting GPS view from my apartment. 
Mounted the TB in my summerhouse, and the TB is running nice there. 
Checked the RB using a Rigol-100Mhz scope & TB as ext-sync, it seems to 
be spot-on.

But i had to bring the RB back to my apartment. and read the RB could 
change just by flipping it upside down. What would happen during 
transport home ?? (The bug hits again)

Bought 2 more of the "Cheap" FEI-5080A (15v+5v vers), for apartment & 

Added a few Jupiter-T GPS receivers ... Just in case ...

Had a China freq Cntr. in the summerhouse (has int-freq out on bnc , but 
no ext-freq in). 

But the 10Mhz was "dancing" , when measuring the TB.
Taking it apart revealed a "tin box" on the back with a 13Mhz xtal & a BJT 
for heating. And an ATmega8515 as MCU.

Hmmm ... Didn't i see some 26Mhz goodies mentioned on the list ?

Built a separate (LDO) psu for the OCXO , stole some power from the 
counter-trafo , added an ACT74 for 13Mhz. 
And now the display shows 10.000003 mostly , can show 0..3.

I hope to get 10.0000000But i still need to add a fine adjust pot to the 
OCXO , only had a 10K single turn). Nice OCXO for the price , and very 
fast to get stable. 

Saw the X72 on eb.. , and read that it was GPSDO'able.
Had to get one , and then i discovered the GPSDO feature was in fw 5.x , 
mine had fw 4.x. Well nice little RB.

Needed a backup for my PM-6674 , maybe with some more digits & GPIB ....
Got a HP-5384A (Only GBIB option so just "plain" xtal) , calibrated it 
against the TB in summerhouse , and brought it back home. Nice little 

But i still need to adjust/verify my PM-6674. 
And what about the HP it "only" has an Xtal.

I do still need a Tbolt in the apartment , toyed around with a Jupiter-T 
and got GPS lock outside bedroom window 30 cm from the wall. Making 
antenna fixture to be mounted on wall.

Saw TBolt price rise on eb.. , had to get one now ... 
And a spare.... (bug bites again).

Today : Got TBolts
But we're getting a new roof on the appartments , so the whone building 
is surrounded in scaffold. Taking the GPS view .....

So i'm still waiting to calibrate my PM-6674 :-)

And now back to the Racal-Dana 1991 or 1992 Counter question.
I might need a TIC , and the HP5070 + shipping is to much.
So i was wondering about one of the above mentioned Racal's.

I have a nice offer on a 1991 , but can get a 1992 also ?
Witch one would you recommend for general "Nut usage".

73 de OZ1FTG

Ps: I suppose the above sounds familiar.
    Has anyone found a cure the yet 

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