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QCX first WSPR tests with GPS

f6dfz@...
 

Dear all,

Today I did my first tests with the GPS on WSPR mode on 40 m.

As it had been said elsewhere on this reflector, you absolutely need to set menu 4.7 Practice to On, and to have your QCX on a dummy load when connecting the GPS. If you don't do that, your PA will very quickly go south as the QCX transmits instantly.

The GPS works great and is sensitive. Don't forget that the GPS sets the time and the frequency at the end of the first transmission, so if menu 4.7 is ON, your QCX will be time and frequency corrected without going on the air.

Now its time to set menu 4.7 to Off and go on the air.
If you didn't fit a heatsink on the 3xBS170, the only totally cool and safe power is with a power supply of 7,5 V . With mine, on 40 m, I get 1,5 WHF output.
AT 9 V power supply, I get 2 WHF, but the 3xBS170 are very hot, and certainly will not last long.
At 12 V power supply, I get 3,5 WHF, but the 3xBS170 are intolerably hot, and you can smell the warning odor of a nearby failure...
AT 13,8 V power supply, I get 4,5WHF, but I only did a quick test. It can be OK for CW.

It's always amazing to see your signal from such a tiny rig spotted at long distances.

The next task is to do a heatsink to protect the PA.

All in all, this rig is outstanding, and very impressive;

Best regards

Georges F6DFZ

Kees T
 

Great info, Georges. Thank you for providing the summary.
 
I'm also going to sandwich the 3x BS170s in between a heatsink and a small flat plate behind them, tapped for 2 screws. Similar to what SoftRock did.
 
73 Kees K5BCQ


---------- Original Message ----------
From: f6dfz@...
To: QRPLabs@groups.io
Subject: [QRPLabs] QCX first WSPR tests with GPS
Date: Thu, 28 Dec 2017 09:14:25 -0800

Dear all,

Today I did my first tests with the GPS on WSPR mode on 40 m.

As it had been said elsewhere on this reflector, you absolutely need to set menu 4.7 Practice to On, and to have your QCX on a dummy load when connecting the GPS. If you don't do that, your PA will very quickly go south as the QCX transmits instantly.

The GPS works great and is sensitive. Don't forget that the GPS sets the time and the frequency at the end of the first transmission, so if menu 4.7 is ON, your QCX will be time and frequency corrected without going on the air.

Now its time to set menu 4.7 to Off and go on the air.
If you didn't fit a heatsink on the 3xBS170, the only totally cool and safe power is with a power supply of 7,5 V . With mine, on 40 m, I get 1,5 WHF output.
AT 9 V power supply, I get 2 WHF, but the 3xBS170 are very hot, and certainly will not last long.
At 12 V power supply, I get 3,5 WHF, but the 3xBS170 are intolerably hot, and you can smell the warning odor of a nearby failure...
AT 13,8 V power supply, I get 4,5WHF, but I only did a quick test. It can be OK for CW.

It's always amazing to see your signal from such a tiny rig spotted at long distances.

The next task is to do a heatsink to protect the PA.

All in all, this rig is outstanding, and very impressive;

Best regards

Georges F6DFZ