PGXL Genius amplifier persistently shuts Down detecting “high SWR“

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My brand new genius amplifier has been working flawlessly over the past month or two that I’ve had it. Along with my flex 6700 and my 8 X2 Green Heron antenna switching device, I can operate from 10 m up to 80 m with the use of my three antennas including my mostly pro 67, my slope or dipole and my 80 m vertical Antenna. Everything works great on 10 m through 40 m on all antennas. Sometimes I have slightly elevated SWR of 1.5:1 and for this I really use my palstar HF auto tuner Which I use just to keep things as close to 1:1 SWR. For unknown reasons and only on 80 m whether I am on my sloper dipole or my 80 m vertical r, my tuning shows that I am at 1:1 SWR but then when I increase the RF output much above nine or 10 W which typically will produce do you 150 to 300 W output of the amp, I suddenly get a “high SWR“ warning and the amp instantaneously stops transmitting. Yet when I recheck SWR it is 1:1.???

I’ve never had any common mode RF problems before but everything else looks fine and this only happens on 80 m. But it happens on two completely different antennas but again only on 80 m. Every other band is perfect. The genius amplifier states everything boots up fine and I rebooted everything up a few times but it persistently keeps on happening. Any suggestions are appreciated!
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kjave63@yahoo.com

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Posted 1 month ago

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Bill -VA3WTB

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AC9S unless flex has already sent you the shipping documents or it is already shipped, maybe check out  the power supply under the cover. In some cases the the amp has been handles badly in shipping and has caused the power supply to move back away from the plug in socket it mates with. Is it possible that yours is plugged in but not securly?
(Edited)
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AC9S

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Thanks Bill,

I am also having them look at the HI SWR problem that I have on 40.

Keith - AC9S
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kjave63@yahoo.com

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FYI/important follow up: I’m still waiting on Flexradio engineers to get back with me, HOWEVER I am now noticing increasing SWR on 40 m and while I don’t get a red warning and shut down, I’m now seeing these issues on 40 m when I increase the input from 20 wants input to 25 W and put I get a moderate jump from 1:122.2:1 SWR. Again however with my other amplifier that is a solid-state SPE 1.3 K, no jumping SWR whatsoever at any range on any band.
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AC9S

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After pulling the PGXL and packing it for shipping I put my trusty Alpha 8410 back in line and ran a full 1500 watts on 40 meters into the SteppIR with the SWR remaining at a nominal 1.03.  Clearly the HIGH SWR is a function of the PGXL.  Hopefully when I get the PGXL back from Flex it will have a functioning power supply and will work without issue on all bands.

Although it is a little noisy, the PGXL certainly puts out the power and the integration with Maestro and SmartSDR is impressive.

To keep it in context this is a new amp and the kinds of problems we are experiencing are similar to  other new designs.  My Alpha 99 had to be returned to the factory once and my 8410 had a problem, inadequate screen resistors, that I was able to correct with a little guidance from the factory and their shipment of replacement parts.  Since then it has been a horse for the last 10 years.

Kind of like warfare I'll bet no new design survives first contact with the customer.  At least we aren't dealing with a 737 Max.

Keith - AC9S
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Burch - K4QXX

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Keith, keep us updated on what Flex says about your amp.  I have the same high SWR issue on 80 meters and I really don't want to ship back unless I have to.
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kjave63@yahoo.com

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I most certainly will.  So far I am continuing to update Flex, and I do get a quick (copy and paste response?) response back "thanks for the information, I will pass it on to the engineers and get back to you".    That's all I have for now.   Not sure how their process works.   Frankly, I am not certain how I (or you) can remedy this situation without sending it back, as I am willing to bet this cannot be taken care of "remotely" or with another Firmware update (as I am using the latest version of PGXL and SmartSDR they have for download right now).   I strongly suspect some components have to be replaced or even entire boards need replacement.  Perhaps even the amp?   But not sure what more information the engineers would need that would be useful.   I can't get my amp to work on the low bands, and it also acts improperly on 40 as well.   As soon as I here anything, I will let the group know.  

FYI, I did tell Tim at Flex, that this particular problem is not "rare" and others are having the similar / exact problems.   No response except that the engineers will be made aware.   I am OK with sending my AMP back (not happy about it), but so long as it's fixed in a timely fashion (2 weeks???) or a new one , I am OK, but I don't want to be off of 80 without QRO the entire winter.

Keith KJ8DO
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kjave63@yahoo.com

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UPDATE: Hello all, as the original poster of this issue of the “HIGH SWR” noted particularly on the local bands such as 80 m, 40 m and reportedly 160 m, I am scheduled to have my PGXL amplifier returned to me from Flexradio after they discovered the problem! The problem is due to the 80 m filter capacitors were burned up on the filter board. The reasons were of how and why were not given , but since I was starting to have issues on 40 m of Rapidly claiming SWR readings during 10 to 20 seconds of transmission despitefully resonant antennas as well as complete inability to transmit at all on 80 m despite fully resident antennas, apparently there is some sort of problem that caused complete burn up of one of the 80 m capacitors on the filters and Flexradio was kind enough to replace the entire filter board just in case this was starting to happen on 40 m and possibly 160 m.

Flexradio was kind enough to replace the entire filter board just in case this was starting to happen on 40 m and possibly 160 m.

I have not received the amplifier back yet but it has been shipped back to me. I will give kudos to Flexradio for getting right on this problem and they state that pre-shipment testing shows everything working properly on all bands at for legal limit transmission. I will further update this once I get the actual amplifier hooked up to my systems again however I just wanted to relay this information in hopes that it might possibly be useful to some of those out there who are having similar problems. Mr. Patterson one of the lead technicians At Flexradio did not offer any theories on how or why the capacitors on the 80 m filter literally burned up, only that he confirmed that it did ( and he stated that nothing I did or didn’t do contributed to this failure) and hopefully I won’t have this problem again.

Perhaps someone a lot smarter than I and a lot more experienced than I could possibly suggest some theories as to why these capacitors particularly on 80 m and other low bands are susceptible to “burning up“
.
I thought this would be useful and I again want to thank Flexradio for getting my amplifier back to me in a relatively short period of time.
Keith
KJ8DO
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Sergey Abrikosov

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Received? Tested? Fixed?

Mine went to Flex last week.
Sergey, KN7K
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kjave63@yahoo.com

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Update:
My PGXL was sent back to Flex. The capacitors on the 80 meter filters were completely burned up and the 40 meter filters were almost gone as well! They replaced the entire filter board. It is now back home and so far all working well!
Time will tell, but what I don’t know is “will this happen again??!!” They stated “you did nothing wrong”. So I am very glad that flex radio repaired the PGXL amplifier and so far so good for the past 1 1/2 weeks, but if no one knows what the problem is or do too, I fear that this issue will return again? Any theories would be appreciated.

But kudos to flex radio for getting my radio back to them and then repaired and back to me and barely over three weeks total time.

Keith
KJ8DO
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AC9S

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A bit of an update on my PGXL.  The amp was returned in short order from Flex service with the power supply fixed. 

Subsequently a Flex rep and a rep from 403A Team Viewed into my shack to run diagnostics while I recreated the High SWR problem on 40.  They were pretty thorough in running multiple permutations of the problem; the session was well over a half hour.  I just received a nice thank you from Flex which stated my problem was consistent with what other customers were reporting and that they were hot on the trail to identify root cause and corrective action.  I am sure they will nail it at some point; we just need to be patient.  My amp works at low power on 40, so for CQWW I ran it at 350 watts on 40 and the legal limit on the others.


Once the High SWR problem is corrected my only complaint will be fan noise.  I wish the fans would remain off until one of the temps exceeded a threshold - like PA > 40C.  The fans go off when PA temp is lower than 40C in standby, just wish there would be a setting to enable the same action in operate.  Maybe a S&P contest mode which is what I did most of CQWW in.  --Keith - AC9S


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WX7Y

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My AMP is on it's way back from FLEX right now after my LDMOS devices failed during testing with Eric with the High SWR problems. 
What caused the LDMOS MOSFETs and SWR problems was Shorted Caps in the Filters on 160 and 80 Meters. 
Hope this took care of the Problem for my AMP and it will keep working now for years and years, All I can do is cross my fingers and hope it doesn't happen again. 
Thanks to FLEX's GREAT service dept and specifically John for very quick service and keeping me informed on the progress and getting it turned around, now just hope UPS is gentle with my AMP and it works when it arrives home on Friday. 

73 and good luck
Bret
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kjave63@yahoo.com

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Ditto! I had similar excellent customer repair service!
KJ8DO
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Burch - K4QXX

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I guess I need to open a ticket with Flex as I can't run more than about 400 watts on 80 meters before I get the high SWR shutdown. 
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HCampbell WB4IVF

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Has anyone been told whether the PG XL's that are being returned for service have also been retrofitted with the new stronger PS mounting bracket (to prevent shipment damage that was previously reported in this forum?)

Howard
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WX7Y

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I will get mine back Friday, but NO I was not told about a retrofit Power Supply retainer bracket.

Bret
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HCampbell WB4IVF

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OK, thanks Bret.  In response to postings of shipment damage, Dan mentioned a few months back that Flex was expecting a shipment of stronger brackets from 4O3A a few months back and that they would be shipped to all PG XL owners.  I thought I'd ask if anyone had any new info.

Howard
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Kevin Darrah

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I've been wanting to order one, every time I check they say their not available. I thought maybe they weren't even selling them yet, but anyway, good luck with yours guys, hopefully have one sitting here soon.