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FT8 Power Pou


 

On 20 Meter FT8 I am only getting 7 watts output. Seem low to me. Yes the drive is at 100. I am using a PI4 with 8GB and running the 64 bit version. The antenna is a resonant 20 meter vertical.

Any suggestions

Joe N7QPP


 

You must do power calibration. Instruction on sbitx.net.
Bye
Carlo


Il 10 Giugno 2024 01:21:50 CEST, joe camilli <jjcamilli@...> ha scritto:
On 20 Meter FT8 I am only getting 7 watts output. Seem low to me. Yes the drive is at 100. I am using a PI4 with 8GB and running the 64 bit version. The antenna is a resonant 20 meter vertical.

Any suggestions

Joe N7QPP


 

开云体育

This was not a kit unit. But a unit purchased assembled at Hamvention.

?

Joe N7QPP

?

From: [email protected] <[email protected]> On Behalf Of Carlo Piga
Sent: Monday, June 10, 2024 2:16 AM
To: [email protected]
Subject: Re: [BITX20] FT8 Power Pou

?

You must do power calibration. Instruction on sbitx.net.
Bye
Carlo

?

Il 10 Giugno 2024 01:21:50 CEST, joe camilli <jjcamilli@...> ha scritto:

On 20 Meter FT8 I am only getting 7 watts output. Seem low to me. Yes the drive is at 100. I am using a PI4 with 8GB and running the 64 bit version. The antenna is a resonant 20 meter vertical.

Any suggestions

Joe N7QPP


 

Joe:

The power output of mine was OK for about 20 minutes, then dropped to zero. Repositioning the radio on its back suddenly restored a few watts of power out, suggesting a bad solder connection or fractured SMD

I have seen various reports of problems similar to what you report, discovered early in factory-made units. ?Some who have reported low power out have replaced SMDs (resistors apparently) in the driver section, leading me to believe thermal expansion of the board compromises a connection or a component. The problem with these reports is that they usually don't offer a diagnosis, so we don't know what the original problem was. ?Just the act of re-soldering a bad joint might have been the real fix. You could also have a bad MOSFET. ?You'd lose half of the push-pull output. ?Or, it could be the drive pot has failed. ?Or a transistor in the driver. Or a software/RiPi issue. Unfortunately, lots of things could lead to your symptom.

If it's a new unit, you shouldn't need to be repairing it.

My advice would be to contact the makers. This forum has a few similar reports of low output power, and I'm hearing of others. ?If there's a quality control issue in manufacture, I think they should know of it so it (and your radio) can be fixed. ?

Jim
WB0KWJ


 

Thanks for the feedback. I have sent an email to HF Signal via their sales email address. We'll see what they suggest as a course of action

Joe N7QPP