LBE-1421

[brandon7861]

If I disappear from the internet, it's because my girlfriend got the mail.

This looks like the neatest GPSDO I've ever seen, and now it is going to be the heartbeat of my homebrew 11m radio and the motivation I need to actually start building it.

LBE-1421 2-port GPSDO locked clock source : Leo Bodnar Electronics

Leo Bodnar Electronics LBE-1421 2-port GPSDO locked clock source - GPSDO-locked frequency source with 2 low-jitter outputs and switchable 1PPS on output 1. Output 1: 1Hz to 800MHz and 1PPS, Output 2: 1Hz to 1.4GHz Datasheet v1.0 This device outputs high purity signal with frequency locked to...

www.leobodnar.com

edit: not trying to promote anything, I just thought it was a cool thing others may be interested in. Being able to set fractional integer frequencies on two different ports is cool. It can also output 1pps clock or GPS data. It comes with windows software, you just type in the two frequencies and it does it. No arduino/stm32, no code to learn, no clumsy Chinese knob and display. And it looks clean. One youtuber reported spurs on fractional integer UHF frequencies, but it was clean at HF. I hope it was worth it.

 

[brandon7861]

Should I be nervous???

I ordered this yesterday, shipping from Wellingborough, England, and now today it says it is out for delivery here in Minnesota. I know all of our FedEx packages go through Bemidji, and they have been rumored to use terminal 1 at Bemidji airport for international shipping, but this just doesn't seem right. I will update later if it actually arrives. I have a bad feeling about this.

detailed tracking looks legit, but never in my life have I ever seen an international shipment move that fast.

EDIT: Well, I am impressed. It actually arrived. 3900 miles in 38 hours!

 

[brandon7861]

Update:

I didn't have time to let anything really warm up properly, but within about 10 minutes of both running, the GPSDO and the ebay rubidium standard going into the scope XY mode were drawing a nearly still image. With the HF radio in the shed, I never did check the rubidium standard against WWV, but now I know that's right too. Before I shut it down, I was having trouble noticing any movement in X-Y mode, so I am going to bed very happy.

I aligned my FC using the rubidium standard about 4 months ago and I see it is already 15Hz off. I guess that can be expected for a cheap counter. I also noticed that my oscilloscope has jitter. When I had both 10MHz signals connected to it, both signals appeared to jitter, but both channels did so the same amount and in the same direction. I've noticed that jitter before and always assumed it was the signal I was probing, but seeing it do it to both channels the same, I now know that it's in the scope itself.

Is it normal for scopes to have jitter matching their rise time limitation? Its a 200MHz scope with a measured rise time of about 1.5nS, and that matches how far the corners of the signal moved. Edit: it didn't matter if I triggered on the GPSDO (300ps rise time) or the rubidium that outputs a sine wave. Maybe the picoscope has a crappy oscillator.

 

[brandon7861]

Just a note for anyone considering this GPSDO.

The outputs have a DC offset. I didn't realize that at first and my counter wouldn't settle. Use a blocking cap! I was too cheap to buy the low pass filter so I included the blocking cap in the pi filter I made. From the SMD parts I had on hand, I was able to make a decent low pass pi filter for 10MHz. I used 1nF COG 1206's for the shunt caps, a 0.47uH RF inductor (same footprint) for the series element, and a 100nF for the blocking cap.

I am super happy with this thing, I highly recommend it!