PGXL

Bill AB7AA

My PGXL drops off if transmitting into a 40 M antenna with 1.5:1 SWR or greater.  Same type of problem that it used to have on 80/160M before the latest firmware update 3.2.15 fixed it. Flex boasted that it would handle 3.0:1 so I thought that it would give me full 40 M antenna bandwidth but it is more limited than my Alpha 87A.  Can the same fix that was implemented to correct the problem on the lower bands also be used on 40M? 

I have yet to resurrect my 40-10M log periodic antenna that has varied SWR below 2.5:1 on all bands that I suspect might also exhibit the same problem when I get it back up.  Why not use the same fix on all of the bands?

Bill AB7AA

bahillen

Try turning off Meffa. I don’t understand what it is doing specifically, only on a general basis. When I turned up PGXL power SWR would go up above 300-400 watts. And would het a HISWR screen on the PGXL utility. I thought I has an antenna problem. I turned off Meffa in the tools as I recall and everything worked fine. No hi SWR and no strange behavior. I was using on WSJT and they indicate Meffa is for CW and SSB. Doing to many other things to investigate. Thought this may be helpful. 73 Bill W9JJB

Bill AB7AA

Brian Morgan VK7RR

NX6D Dave

Bill AB7AA

NX6D Dave

Bill AB7AA

Jim K4JAF

Sure glad I did not purchase a PGXL when first offered....  

bahillen

Jim, you are missing an outstanding amplifier. There are new things that it does that are easily picked up. Changing bands and power is just where I set it in prior Q on that band. I worked in the digital contest and 50% duty cycle at 1.5 KW. Solid. It is a commercial quality amplifier. I couldn't be happier. Remote operation is a breeze with the amp.
73
Bill W9JJB

Brian Morgan VK7RR

DH1RK

[Deleted User]

My KPA-1500 just hums along and it has a tuner in it.

Clay N9IO

Bill I would open up a help desk ticket and have them help you sort this out. I don't think you're going to find your answer here.

Burch - K4QXX

Bill AB7AA

Bill -VA3WTB

The PGXL has been tested extensivly on 80 meters. I have talked to a few people on 80 meters and they do not have any problems. In your case it is hard to know what is causing your problems. I hope the Help Desk can help sort it out.

KL4QG

What is PGXL

Bill -VA3WTB

Joe, it is the Flex amp

KL4QG

Ok thanks

Asher - K0AU

bahillen

What happens on a dummy load. What is the exciter power to get 600 watts on 40 m. Try a test with measuring drive power to get 100-600 watts in 100 watt increments, it it linear input vs output. Check the various places that control max power. For testing set max power to 100 so the software is not confusing your analysis. Try a through line wattmeter between flex and PGXL. I would turn off Meffa during test to prevent confusing data. Different bands and load reactance can require different drive requirements. 1.06:1 doesn’t necessarily mean 50 ohm resistive and the PA may not necessarily be 50 ohm resistive. Check antenna with antenna analyzer and look at R+jX. Try putting a 10 foot extension to your antenna feedline. It will rotate the impedance around the Smith Chart and change what is presented to the PGXL. You may be surprised at the change in match between PGXL and antenna. Remember that a solid state amplifier has no tuning so it may be different in a way you wouldn’t expect. The above may have nothing to do with you problem but may help to analyze these kinds of problems. Let us know what you find as it can help others. I have seen some different behavior on various bands some requiring more drive than others an I set my max drive power to 50 watts. Rain and ice on the antenna changes my antenna SWR. 73 Bill W9JJB

Asher - K0AU

bahillen

In your first table, 20 watts produces 573 watts and 40 watts 633 or .4 dB. On 28 MHz 20 watts is 819 and 40 is 1316 or 2.1 db. With 3 dB drive The amp is cutting back on 40 m. If you can compare on a 50 dummy load it would be helpful to know. With the PGXL utility check the temperature to see if temperature rise is similar. Use 20 watts and 40 watts with the two different bands, 40 m and 10 m . This info would help with a help desk ticket. Did you try to add a 3 to 10 feet feedline length change. I just thought you could have a pl-259 connector problem. It would not surprise me to find an insulator in the antenna leaking over. I have had two fail in the past with similar confusing behavior. Lightning arrestors can also degrade but have no experience with this. I did choose 3 kv arrestors because of surprisingly high voltages that could be seen or a weather event. 73 Bill W9JJB

bahillen

Time to open a help desk request. They have experience with this behavior and can react quickly. Try to borrow a 50 ohm load. What release of software are you running? 3.1.8? If so have you tried 2.4.9? 73 Bill

Tim - W4TME

Asher, please open a HD ticket for this issue.  I suspect there is an issue with the 40m filter.

Asher - K0AU

Tim,

Will do. Thanks!

KF4HR

bahillen

Ralph, When I had problems, the insulators developed a leakage path across the insulator. SWR was low during tuning as power increased the leakage increased and SWR would go up. And amp would cut back. Eventually the insulator shorted with some flame. This has happened twice on wire antennas. I have been changing insulators to ceramic or glass. My belief is that operating in snow and ice started the problem. Asher’s problem is probably different as Tim made a comment that the 40 filter is his suspect. I am anxious to hear what solves his issue. 73 Bill W9JJB

KF4HR

Thanks for the reply Bill.  It sounds like your PG-XL was doing what it needed to do to protect itself.  I suspect the SWR peaks may have been higher than what was being indicating, perhaps due to Ethernet communication latency.

Did the problem disappear when your PG-XL was fed into a dummy load?

Brian Morgan VK7RR