TA-0305: Rapco 1804p9 vs BG7TBL GPSDO a 2nd look

[@bobwhite137]

Just as an FYI, if it took 22 minutes for one cycle to "cross" (in the video, you showed 11 minutes for what appeared to be 1/2 cycle shift) - that would equate to roughly a time accuracy of 1 second in 418 years. Not bad!

[@TonyAlbus]

Thanks! that is great to know... good i did it on 10 MHz and not 1PPS... would have become a long timelaps :)

[@ИльяКоротаев-б9я]

6:00 синхронизация, фазовый сдвиг!☕🙋

[@TonyAlbus]

Oh.. i am not i timenut, not sure what that is.

[@M5AXA]

Nice one Tony. Precise and informative as ever. The Rapco looks great across the top of those draw cabinets.

[@TonyAlbus]

Thank you Ian! The Rapco feels at home here.. even the colors match :)

[@ivolol]

I've also heard you can get timing GPS chips if you are building these sorts of things for labs, they don't care so much about position at all, all they care about is getting spot on timing errors to a minimum. I think for this, they assume that whatever position they are in currently, it is fixed (your equipment is staying in the same place on Earth) so it can start improving relative accuracy deviations in the timing calculation from there. Whereas a regular GPS chip, a smaller timing error is cross-correlated to how well it can calculate an accurate position, but it doesn't ever assume it is stationary, so it has one less constraining variable it can use to narrow down error.

[@TonyAlbus]

Thanks Matt, interesting point indeed.

[@Flamenawer]

The thing to improve is a M8T, LEA or NEO, as they are focused in that. You can use NEO-M8T and it will be compatible and transparent with the M8N of any gpsdo use one . LEA m8T is not pin compatible, but it is even better for these tasks, usually is communication towers etc

[@sammin5764]

🌟🌷🌟

[@TonyAlbus]

Thank you!

[@sbelectronicaindustrial6652]

Hello, what a good frequency meter ... Greetings Tony

[@TonyAlbus]

Thanks, yes love the FA-3 for these kind of jobs.

[@germibestia]

Hi Tony, thanks for the interesting videos. I have gotten myself one of the BG7TBL GPS receiver, the FA-3 frequency counter and the 10 MHz distribution amplifier and I have a question: On bot the GPS receiver and frequency counter we see a display telling us the frequency with great precision. But How can we be sure about the accuracy of those readings? If we use the GPS signal as reference, the frequency counter assumes it is perfectly 10 MHz, so what if it's slightly out? It gives us readings down to the 0,1 micro Hz!!! And the frequency counter of the GPS receiver itself, how can we be sure it is accurate to the 0,1 mHz?

[@TonyAlbus]

The display shows the current setting of the TCXO compared to the GPS time (atomic clock) so if it is a bit off, is will try to compensate.

[@germibestia]

@@TonyAlbus thanks for the answer. Are the exits of the distribution amplifier 50 Ohm or high impedance?

[@TonyAlbus]

@@germibestia Hi, they are 50 Ohm

[@M-P-X]

Volgens mij kunnen de modernere GPS ontvangers zoals de NEO 8 toch wel minimaal 66 kanalen aan?

[@TonyAlbus]

Ik heb het niet kunnen vinden, ik zal verdermoeten zoeken, maar 25 doen ze dus in ieder geval.

[@zdzisiek1979]

👍🙂

[@barrybogart5436]

I just wondered if that Kenwood TH-D7 still works. Mine does. Even the batteries.

[@TonyAlbus]

Hi Barry... TH-D72 .. yes is does.. video from last May. kzbin.info/www/bejne/l5PHl2qBl9end9E Great yours works too.

[@barrybogart5436]

@@TonyAlbus Yes, I just found your #283. But it would be really nice if there was a mod to allow WIRELESS connection from the D7 and a GPS. I already have a Bluetooth GPS, so how hard would it be to add BT to the D7 somehow? 73

[@TonyAlbus]

@@barrybogart5436 If you can find a serial to BT adapter, you should be able to do so right? only thing is, modern GPS do 9600bd , i am not sure, but the older Kenwoods usualy expect 4800bd .. that is to look out for..

[@barrybogart5436]

@@TonyAlbus Hams are clever - I bet someone has done it. Years ago.

[@erwe1054]

🤔🤔🤔

[@TonyAlbus]

thank you

[@nebilekedire703]

Hi

[@TonyAlbus]

Hi, thank you