could a VFO mode for the ProgRock be added? a mode that doesn't write the settings into the EEPROM space, one that just updates the registers in the Si5351A to alter the frequency output.

-Justin N2TOH

Bob, Hans & All .............. de John? VK6JY

Back to your design basics Hans, would the ProgRock be inherently more accurate in parts per million if operating at say 50MHz or 100 MHz and subsequently? divided down to 10 MHz??? (ie Less ripple?)? GPS and control optimum.

On 6/11/2017 3:32 PM, Hans Summers wrote:

Hi Bob, all

I see several people have answered this already. This is my take on it all...

What type of precision are you looking for when you say "lab grade"?

The ProgRock when it is properly set up and working properly, should be within +/- 0.5Hz of the desired 10,000,000 Hz. That is, 0.05ppm (50 parts per billion). The frequency "steps" as the algorithm hunts around making corrections, are NOT several Hz, they will be a fraction of a Hz. Theoretically the steps will be sized 0 to 0.3Hz at this output frequency. They depend on the arithmetic with the particular reference clock measurement that is made by the 1pps.?

In order to get this precision, the "GPS correction threshold" register 03 must be set to value 0. This is described in section 6.7 of the manual.?

Joe, Joel, I would be very interested in some numeric data on your units - what kind of accuracy you see and why. I am very interested to know also whether you set the "GPS correction threshold" register to zero. The default value is 5Hz which means that the measured reference frequency must change from the last time by at least 5Hz before a correction is applied.?

There ARE firmware improvements which are possible, that can improve the accuracy. I can work on those if it is necessary. However I still wonder, of the people who find the accuracy is not as good as they expect - have they set "GPS correction threshold"?to zero??

73 Hans G0UPL

On Sun, Nov 5, 2017 at 5:18 PM, Bob <bobc784@...> wrote:

I have several pieces of test equipment that have an input for a precision 10 MHz reference.

Specifically an HP freq counter.

Would a Progrock and QLG1 GPS set 10 MHz provide a lab grade reference for a counter?

A poor mans version of quality reference?

Bob? WA1EDJ

Monroe, GA

Virus-free.

Ben and all,

?

It sounds like you and I are similarly afflicted!? My eyes are not very good either, one having macular degeneration to the point that everything is a blur with that eye.? Thus my vision tends to be 2 dimensional rather than 3 dimensional.? It’s weird!? I’m even close to your 76 year mark—two more weeks!

?

I agree that T1 is a bit daunting, but mostly it is just cumbersome with those 8 legs.? Your method makes some sense, but seemingly has some complications as well.? Admittedly I fumbled around a bit installing T1, but eventually I think I came around to a process that worked pretty well.? It’s a bit difficult to describe, but I’ll take a stab at it.

?

First, you need to make sure that you have the 4 connections on each side of the toroid nicely aligned as they come off the toroid.? I used WA4MZS’s drawing as a guide.? Each connection on the left has an opposite connection on the right, i.e. 7 and 2, 3 and 8, etc., but these leads are only “opposing” in how they are inserted into the board from top to bottom.? They are not the opposing ends of the same winding.? Then I make sure that each successive pair is somewhat shorter than the pair just above it.? 3 and 8 are shorter than 7 and 2, etc.? I work from the “top” inserting 7 and 2 first.? Then I go to 3 and 8, and since they are shorter, they aren’t crumpled too much due to the insertion of 7 and 2.? I “coax” 3 and 8 into their respective holes with needle nose pliers.? Then I go on to 5 and 4, and finally 6 and 1.? Working from “top to bottom” seemed easier than doing the reverse.? Once all 8 leads are inserted in their respective holes you can pull each lead from the bottom of the board to tighten everything up nicely.? Before soldering anything, I checked for proper continuity on each pair that actually opposes each other—1 and 2, 3 and 4, etc.? With 8 leads it isn’t difficult to get a couple of leads crossed, but the procedure I followed seemed to prevent that, or at least minimize the probability.?

?

I’m not suggesting that my method is necessarily better, but once I settled on this process, things seemed to go relatively smoothly.? I fumbled around a bit before coming to this method.? Clipping each successive pair shorter seemed to help a lot—you just don’t want to have the last pair be too short!? This also helps you properly identify each pair.? If all your leads are approximately the same length, it’s easy to get them confused.? I think my lack of “3D” vision made things a lot more difficult in my case, but when I went to dealing with just 2 wires at a time, it seemed much easier.

?

I hope this makes some sense to somebody!!!

?

Cheers,

?

Dave W7AQK

?

?

?

?

From: Ben Bangerter, K0IKR via Groups.Io

Sent: Sunday, November 5, 2017 5:43 AM

To: [email protected]

Subject: [QRPLabs] QCX T1 installation: A better way?

?

I began assembly of my 20 M version of the QCX nine days ago, and all went well thanks to the excellent manual provided by Hans.? Until I got to the most difficult component - the transformer T1.? I had no difficulty winding T1, but when it came to installing it on the populated board - fitting eight thin wires into the proper eight holes in the pcb, essentially simultaneously - that was a bit much for my 76 year old eyes and fingers!? So I removed the three small windings from the toroid, and installed the toroid, with only the large winding, on the board, soldering both leads.? I straightened the wires of the three removed windings and soldered one end of each length in the three outer holes for those windings.? Then one by one I wound those three small windings on the toroid, starting over the top of the core, passing the wire under the core (with the aid of a tweezers) to the outside, and repeating the process until the three turns were completed.? Then I inserted the free end of the wire through the inner hole for that winding.? Verifying that the sense of each winding was correct, I tightened the wires and soldered the last three connections.? This process went very smoothly, and I am pleased with the result.? If you have difficulty with the installation procedure? as described in the manual, you might want to try my method.

Of course, when it came time to align the QCX, the peaking capacitor was fully meshed and I had to add turns to the large winding!? But that went well, and the alignment process proceeded smoothly.? R24 ended up fully counterclockwise, but the image rejection is excellent, as is the sensitiviy.? The rf power output was low, as many have experienced, about 1.0 - 1.2 W with a 12 V supply (increasing as the key is held down for a few seconds).? My first contact (from Connecticut) was with OZ0JX in Denmark, with my 1 W and dipole up 20 ft!? I subsequently raised the power output to 1.6 - 2.0 W by removing one turn from each of the LPF inductors.? And I solved the turn-on issue with a diode (1N5711) between pins 7 and 20 of the ATmega328P.?

Hans has done an incredible job with this project, great hardware design, software design, board layout, and the best construction? manual ever done.? And all at such a low cost!? Plus he spends a lot of time in support of those of us encountering problems and having suggestions or questions about this remarkable little rig.? What a fine contribution to the QRP world and the Ham Radio builder/maker community!

Ben - K0IKR

available in VK from Element14 (Farnell) for about 15c.? Problem is, if you only order under $45 you get hit with $12 shipping

glenn

vk3pe

Virus-free.

I have several pieces of test equipment that have an input for a precision 10 MHz reference.

Specifically an HP freq counter.

Would a Progrock and QLG1 GPS set 10 MHz provide a lab grade reference for a counter?

A poor mans version of quality reference?

Bob? WA1EDJ

Monroe, GA

My antenna broke and high SWR caused my QCX to cook and smell and at least one BS170 is visibly blown. Seems cannot find these locally, is 2N7000 as good? What alternatives can be used that will not reduce power or be more likely to blow?

So if I understand it, using the OCXO/Si5351A with the Progrock instead of the standard non-OCXO 5351A version would be an improvement?

Bob,

I meant a commercial 10MHz OCXO, the QRP Labs one might be able to be setup as good? but I am thinking of probably a around $30 with the advantage of no GPS. (If you think that is an advantage.)

And, as Joe says a modern TCXO like the FOX can be fairly close to that. (Although I've never liked the idea of the frequency jumps of the FOX even if it's never noticed.)

73 Alan G4ZFQ

? ? I suspect you could do better with a good modern OCXO. (Mine stays
? ? within about 0.1Hz at 10MHz over a year checked with GPS.)
? ? But I await John's tests with interest.

? ? 73 Alan G4ZFQ