TCXO / OCXO behavior differences

  • 1
  • Question
  • Updated 6 years ago
  • Answered
Andrew,
Maybe Steve can comment on this but I wonder if there is a difference in the behavior since the 6500 has a TCXO (temp compensated crystal oscillator) and the 6700 has an OCXO (oven controlled crystal oscillator). Below is a partial snapshot from a document I compiled about the stability differences. It's a summary based on what I've been able to gather about the 6000 series but it has not been validated by Steve. The full document has some additional examples and notes. Let me know if you would like a copy.

The link below is to a good article that discusses the differences between TCXO and OCXO devices if you would like some additional details about the benefits of each.

http://www.radio-electronics.com/info...

Regards, Al / NN4ZZ

Note: This topic was created from a reply on the DC power to FLEX-6000 continuously? topic.
Photo of Al / NN4ZZ

Al / NN4ZZ

  • 1853 Posts
  • 672 Reply Likes

Posted 6 years ago

  • 1
Photo of Steve - N5AC

Steve - N5AC, VP Engineering / CTO

  • 1057 Posts
  • 1097 Reply Likes
Official Response
Al,

1. I believe your math is wrong on the FLEX-6700 OXCO -- 20ppb would be +/- 280mHz, not 700mHz at 14.01MHz
2. On the GPSDO, at 5 minutes, the spec is 10ppb accuracy (140mHz) and after 24 hours it is 0.005ppb -- note ppb not ppm (70uHz [microHertz] at 14.01MHz).
3. Just for reference, on the GPSDO with no antenna attached, the spec is 150ppb (2.1Hz at 14.01MHz)

So on a FLEX-6500 with a GPSDO with no antenna, you are still better off leaving the GPSDO on ("installed" in software), but on the FLEX-6700 if you cannot provide the GPSDO an antenna, you are better off to "uninstall" it in software and force the radio to use the OCXO.

Steve