Another interesting local oscillator source device for Grape

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Graham c

Jan 27, 2023, 10:12:00 AM1/27/23
to hamsci-grape
I recently became that Hans G0UPL has updated his old ProgRock device to the ProgRock2.

This is a simple micro controlled si5351a frequency generator that has three user programmable outputs, and can be disciplined with a PPS from a GPS or similar source. 

Inexpensive and will be available very soon.

Not a simple off the shelf plug and play option but should be useful and useable for anyone with some experience.  

Also, in his QRP-Labs shop you can also find suitable GPS modules and a receiver kit and as always, his prices are quite reasonable.

cheers, Graham ve3gtc

Robert Benedict

Jan 27, 2023, 8:33:34 PM1/27/23
to hamsci-grape
Hans kits are exceptionally well documented and easy to use. I have the older ProgRock, VFO and QLG GPS module, not to mention a QDX and a gaggle of QCXs.
The Grape 2 dev boards have a Si5351 and uBLOX GPS built in.

Graham c

Jan 28, 2023, 8:11:17 AM1/28/23
to Robert Benedict, hamsci-grape
" The Grape 2 dev boards have a Si5351 and uBLOX GPS built in."

What is the Grape 2 Dev board?  I have not seen this one before nor does a quick search this morning find anything other than the Grape V1.  Is this the ongoing SDR project?

A single board incorporating a direct conversion receiver, si5351a, GPS module, and micro would be very useful.

cheers, Graham ve3gtc

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Robert Benedict

Jan 28, 2023, 8:17:56 AM1/28/23
to Graham c, hamsci-grape

Graham c

Jan 29, 2023, 12:48:35 PM1/29/23
to Robert Benedict, hamsci-grape

Thank you for the lnk, I was aware of that project but had forgotten about it.

Not a simple build it yourself type of project however. 

cheers, Graham ve3gtc

John Gibbons

Jan 29, 2023, 4:17:58 PM1/29/23
to hamsci-grape, Graham c, Robert Benedict

Grape 2 is a 3 channel (limited by the SI5351 freq synthesis chip) low IF Radio (NOT SDR!) that is in it's final stages of design and testing.

It will consist of 2 boards - the RF board and the Control board.  Since the rigid timing requirements of the data engine preclude us from using a RasPi 4, we went to a RasPi PICO as the data collection engine (NO Operating System to cause timing issues!)

We are currently figuring out how to swallow a continuous > 1.1 Mbit data stream created by the data engine (note: this was originally slated to be done by the Tangerine and is really beyond the scope of the Grape 2, but I'm still trying to adapt...).  

The goal is to have it ready and dispersed to collect data by summer.  It will create raw (binary?) data files that have GPS synchronized data collection and timestamps associated with the 3 16 bit A/D's sampling at 8KHz each (yeah, lot's of data)

I'm in the final stages of bringing up the RF board  and have the control board built to about 60% completion.  

The final raw boards will both be ideally ordered in late February (and yes - 2023....) and built by a contractor in March. Then tested and debugged in March / April.  That's the plan...

John N8OBJ

On Sat, Jan 28, 2023 at 8:17 AM Robert Benedict <> wrote:

Jay Silber

Jan 29, 2023, 4:32:38 PM1/29/23
to John Gibbons, hamsci-grape, Dr. Nathaniel A. Frissell Ph.D.

Hey John,


I wanted to let you know that I’ve moved to Spain and now have my Spanish license, EA7KWG. It replaces WA2UAR. I’m in Almeria, Spain, just blocks from the Mediterranean.  I am no longer anywhere near the path of the 2024 solar eclipse and I gave my initial grape to K3FZT in Philadelphia who expressed an interest In participating in data collection. But if my location is of any value, let me know. I’d be happy to try and collect data for you guys.



Jay R. Silber, M. Ed.


Senior Producer

Simple English Videos

What Hams Do… The TV Show


Office:+1  267 519-1765

Cell: +34 642 93 52 41

Skype: jays2201

Dave Hinerman

Apr 29, 2023, 9:17:09 AM4/29/23
to hamsci-grape
The ProgRock2 is in stock now. I just ordered a couple and the GPS receiver. I want to compare them to the Leo Bodnar GPSDO.

On Friday, January 27, 2023 at 10:12:00 AM UTC-5 wrote:

Robert Benedict

Apr 30, 2023, 6:46:56 AM4/30/23
to hamsci-grape
Good post on using a Progrock as GPSDO here:
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