[time-nuts] Intro & Q: Racal-Dana 1991 or 1992 Counter ?
wb6bnq at cox.net
Thu Jan 19 16:18:51 EST 2012
Yes ! The cure is to get rid of the Phillips PM-6674.
As for the 5680A orientation, just remember what orientation you had it in when
you checked it at your summer home. Then make sure you used the same when back
at the apartment and call it good enough. Otherwise see first comment above.
When you get your Tbolt up and running after the new roof, you won't need the
> 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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