[time-nuts] yet more RFTG thoughts

TheInfamousFlavio at hotmail.com TheInfamousFlavio at hotmail.com
Wed Feb 21 03:21:10 EST 2007

Robert E. Martinson" wrote:
> ...having intermittent "NO GPS" LEDs on, on both units.

I ran into this also.  I bought my XO units later in game from the ebay 
vendor that most everyone else bought from.  One unit had a the wrong card, 
a 6 channel card inside of a 8 channel box.  When I hooked that 6 channel 
card up independantly, it had very weak tracking of satellites.  By this I 
mean, using a known working antenna via a splitter, this 6 channel card had 
fewer satellites being tracking at the same time than my other 6 channel 
cards.  This card would read 1 or 2 satellites and my other cards would be 
reading 6 satellites

So obviously something is wrong with this card.  I suspect, someone returned 
their bad card inside of one of these units to the vendor, eventhough the 
claimed they don't take returns, and I got sold it because it was one of the 
last ones.  The other XO unit I bought, the 8 channel card was completely 
dead and had something to the effect of "broken" written on the case, but 
the vendor had no problem selling it me at top dollar without telling me 
that.  That vendor is very shady and is on my poop list.

----- Original Message ----- 
From: "Robert E. Martinson" <REMartinson at rcn.com>
To: "'Discussion of precise time and frequency measurement'" 
<time-nuts at febo.com>
Sent: Tuesday, February 20, 2007 23:32
Subject: Re: [time-nuts] yet more RFTG thoughts

> All 3 voltages are present as marked at XO-TP400.  The jumper W11-W12
> measures 2.394 volts.  I'm running the pair, XO & RB, but having
> intermittent "NO GPS" LEDs on, on both units.
> With the Ref input/output & the J5 jumper cables disconnected the above 4
> voltages do not change.
> Regards,
> Bob Martinson
> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
> Behalf Of Rich and Marcia Putz
> Sent: Tuesday, February 20, 2007 6:33 PM
> To: time-nuts at febo.com
> Subject: [time-nuts] yet more RFTG thoughts
> Hi All;
> To answer a question first. I believe PLDENB likely means programmable 
> logic
> device enable. Right next to that header is an Altera Max7000 series 
> device.
> What we dont know is, when enabled does that mean the device just wakes 
> up,
> or does it mean the device is opened to be reprogrammed.
> I am still interested if anyone else has measured the voltages on TP400 to
> see if anything is present other than +5 volts. I have not found any mode
> that makes my RFTG produce any voltages other than the 5volts. The DAC
> appears to be dormant. You can roughly follow the traces from the DAC near
> TP400 over to the EFC line to the oscillator. The jumpers W11-W12 is the 
> line to the osc, I measure much less than 1 volt, I would imagine with the
> unit working, it would be somewhere around 3-4 volts!
> Again I have to say I am running the RFTG-m stand alone, as I have no
> RFTG-RB to go with it.
> So as was mentioned earlier , when a 10 Mhz signal appears at the input do
> things start happening, I applied 10 Mhz from my HP5334, but perhaps I
> didn't have enough level, and thats begs a second question; if 10Mhz is
> present there then why would the GPS side be needed at all, unless the
> RFTG-m is somehow comparing the two signals and picking the one in closest
> agreement to GPS. Who knows?
> On a side note, I did a google search on RFTG and one hit was a guys 
> resume
> describing how he designed RFTGs for HP. I'll let a younger and more 
> daring
> person search the guy out and contact him, hi-hi!
> Rich
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