Low output on 6 meters

Smitty W3SDR

With everything going on these days. I'm just now testing it on 6 meters.
And I'm finding about 600 watts + or - on that band only.
Is this a known issue or do I have a defective unit.

aa3ssradio

If your Flex is putting out 600w on 6m . . . Ide say you have a problem

Mike-VA3MW

@Smitty W3SDR did you get this resolved?

AH0U

I am driving my PGXL with a 6700 and if I drive the XL with full 6700 output I can get just about 900 out but the fans instantly go into hyper shock... all in all, I am disappointed with the PGXL on 6....low output and very noisy... its not like that on any other band... and yes the SWR on 6 is 1.2 according to the SWR meter in the PG but my Bird says 1.4 ... My converted SB200 puts out more with less drive and MUCH lower noise.... I think the 6 meter part of the XL is kinda of an after though and not meant to be a real 6 meter killer... other than that, its a nice amp

xl with full 6700 ou

KA9CFD

I am seeing similar issues with the PGXL on 6m. I am doing mostly digital modes like msk144 for meteor scatter and FT8 for DXing as that is where most of the activity is. It takes about 85 watts of drive to get full output but then the output begins to fall off as I transmit. The Amp heats up very quickly after a few transmit sequences to 80c and the power output drops. It doesnt matter if Meffa is on or off. I have been running the fans in contest mode. Not sure if I want to do a help ticket on this as I dont want to send the amp back to Flex with es season upon us.

Jay KA9CFD

Mark_WS7M

Ok I get 1000 watts with 40w of drive so I'd expect if I drove it harder I could get more.

Like others above the amp heats VERY FAST. I mean in 10 seconds at 1000 watts it is going into the red on temp.

This doesn't seem right either. My old SPE 2K FA could run 1000w pretty much all day long on 6m

Mike-VA3MW

@Mark_WS7M

I don't see the same thing at all.

Part of the heat being generated also comes from any harmonics being generated by the radio as it has a harmonic dummy load. This is something you didn't have in your previous amp.

What radio are you driving this with?

73

Mark_WS7M

Mike - Flex 6600.

I was using Tune feature, at 38 watts, from Flex 6600 on 50.150 into PGXL channel A, then output A into HF Auto set to antenna 2 but on bypass. Antenna 2 is a 6 m dipole

Mark_WS7M

I do have an array solutions switch with could be the culprit. I'll take it out and see if different

AH0U

I use a 6700 to drive the XPGL and I cant get more than 850-900 out of the amp and the fans go nuts into full speed almost instantly....and I notice the temp on the final is what goes up.. according to the utility/... I use a 4O3A 8x2 switch but bypass it on 6 meters as it has a terrible affect on the SWR on 6 meters.....4O3A was very kind and sent me a new relay board but it did not help on 6 meters.... If you are a serious 6 meter op. I think that a 6 meter amp or a conversion would be a better and cheaper choice ... the PGXL is a state of the art amp and great on the HF bands but on 6 meters its not the best out there..... my personal solution is to put my converted SB220 online on the 6 meter antenna output of the Antenna Genius 8x2 so whrn I select 6 meters on the 6700 its output is routed to the antenna via the SB220... the SB220 is a true instant on no warm up[ amp so I use a 220 volt remote switch and when I need the amp, I hoit the switch and its ready to go... no real noise, unlike the PGXL which sounds like a 747 taking off and it gives more power... just my red neck work around

AH0U

P.S>

My experience with the PGXL on 6 meters makes me wonder about the the upcoming antenna tuner and its performance on 6 meters.... might be a disappointment too???

bc

Brian K0BUS

Has anyone opened a ticket?

Mike-VA3MW

If you believe your amp is not making full power, please open a support ticket.

However, it is HIGHLY recommended that you invest in a good high power dummy load and watt meter when doing any wattage measurements. That is the only accurate way to measure accurate RF out. Don't forget, watt meters measure all the energy going out the feedline including harmonics.

When using an Antenna with feedline, your measurements can and will be different than lab measurements.

Also, the heat readings are not all from the Power Amp, but can also be from the Harmonic Dummy load and if your Radio has higher than normal harmonics, those can be amplified and then captured and turned into heat. Watch the videos on how the Harmonic Dummy load functions to understand it.

73

AH0U

I measured the output using an Alpha 2100 dummy load and a Bird 43 as well as a Array Solutions meter so I am fairly confident in the readings.... as for the temp, according to the software, my Harmonic load seems to remain fairly constant in the middle twenties but it is the final that heats up almost instantly... since I am driving the PG with a 6700 I would assume... always dangerous... that the harmonic level is low.... But what I have learned with the Antenna Genius 8x2 is that 6 meters is an "add-on" and for serious 6 meter work, another solution, as my using the SB220 is a better way to go...... Thanks for the input and suggestion but I will stay with my current setup and avoid the support ticket

bc

Mike-VA3MW

@ah0u

I would recommend the support ticket with the amp not making full power. It gets handed to the PGXL specialist. That is all he works on.

Make sure you share your findings.

73

Sergey KN7K

i can easily drive 1700w on 6m without crazy noise, normal as other bands. Also, PGXL is going through AG8x2 with no problems.

Open ticket. Good luck!

AH0U

Tnx Sergey.. that is not even close to mine... it even sounds different on 6 meters than on the HF bands... like it is blowing out some other vent but with 900 watts max is all I get and as soon as it goes into 'TX with a clanging noise, the blower jumps to high and ion a few seconds it is full max... you cant hear another operator talk to you right next to me... very noisy.... I turned in a ticket but dont plan to use the PG on 6 meters ... it even has a high SWR when on bypass on 6 meters... well 2.3 and only 1.2 without PG in line... as far a the AG goes.. it causes the SWR to jump too... this is my thrid one.. first two failed totally and were replaced ans this 4O3a sent me a completer relay board so it works but adds a lot to the SWR so I bypass it on 6.... just my work around but all I can do

73 es tnx bc

David Decoons, wo2x

What are you using for SWR metering? Just curious? I have the PG XL and 4O3A 2x8 and do not see the SWR changing like you are.

Also what mode are you measuring power in? The power metering on SSB in PG XL is very poor. You must use Tune on radio to get accurate reading.

73

Dave wo2x

Dan-N7HQ

If you are not seeing legal limit output on 6m, there is a problem somewhere. @AH0U I created a support ticket for you.

73,

Dan, N7HQ

Mike-VA3MW

Just an FYI for others reading this, this is a unique issue and not related to PGXL's as shipped.

I have reached out privately to see what we can do to help.

Mike

Mark_WS7M

I want to add that I have a 6m dipole, 12 feet off the ground, feed by DX-Max 400 coax.

My rig expert shows it at virtually 1:1 across the band.

Yet trying to run FT8 on the PGXL is pretty much a no go.

I set my output to drive the PGXL to 500w out on 6m and in a 15 second transmission the heat meter goes mostly up to the red. There is no way that I would make 1000 or 1500 watts out for 15 seconds.

I know the antenna is good. The SWR is perfect the cable is good so I have to suspect the amp.

Just to be sure I will test the PGXL output into a 1500W dummy load and see how it behaves

I think I need to open a support ticket too.

Mike-VA3MW

Mark

Please open a support ticket to follow up on this.

Please include any screen shots showing the temperature gauge. I would also make sure you are running in Contest mode.

FT8 is a constant carrier mode and it will cause the PGXL to get warm. 50-60C is normal. I have tested FT8 on 6M at 1000 watts out into a Dummy load for 30 minutes straight with the temperature hovering around 49C. In Canada, I can only legally go to 750 watts for all digital modes including RTTY. CW and SSB are different.

Also, please post a shot of your Audio Level meter and make sure that you are not overdriving the audio section. You need to be with the audio less than -5db.

You also want to ensure you have MeFFA enabled as that points the amplifier in a more efficient operational mode.

Your dummy load test will help. Also inspect your cables and make sure they are correctly soldered including the ground braid. We are seeing some high power issues related to substandard cables. (I am sure they are fine, but I just have to ask).

Mike

Mike-VA3MW

@Mark_WS7M

Hi Mark

Here is a screen shot of me running just now on 50.313 with 741 watts out showing the Mic level and the temperature reading of 53C, which is normal. Amplifiers do get hot and anything less than 80C is ok.

73

Mike-VA3MW

Now, 5 minutes later, I have turned on MeFFA and I am using 60 watts drive instead of 25.

The Vdd is now 29.9volts from 51.9v and we are running a few degrees cooler, down from 56C to 46C.

And I really don't need to run that much power, as I have no issue being heard. I'm now back to running 25 watts.

Mark_WS7M

Hi Mike,

This weekend I will test driving into my dummy load and will try those various options and do screen shots and recordings of the activity/temp.

I will first post that here, if you want, then will add it to the help desk ticket.

Mark

Mike-VA3MW

After you grab your data and if you still have a concern, don't wait for this community, just go to a support ticket please.

Mark_WS7M

ok

Mark_WS7M

Help desk ticket submitted. Is any one is interested here are two movies of the rapid heat up of my PGXL on 6m.

The first one is 500w into a dummy load with meffa OFF:

PGXL-500W-6M-DummyLoad.mp4

https://www.dropbox.com/s/nfc3uuoki63zy4n/PGXL-500W-6M-DummyLoad.mp4?dl=0

Shared with Dropbox

The second one is 1000w into a dummy load with meffa ON:

PGXL-1000W-6M-DummyLoad.mp4

https://www.dropbox.com/s/ukgi9fab3fwbjl0/PGXL-1000W-6M-DummyLoad.mp4?dl=0

Shared with Dropbox

While I don't have a movie of it, I used to run my SPE 2K FA on 6m at 1200 watts and it hardly even spun the fans up much. The PGXL almost pushes the table over at 1000w with the fans screaming.

Mark_WS7M

I will say that I found my amp had been reset to "normal" mode instead of contest mode. Contest mode helps a lot with the temp so I may not actually have an issue. Not sure how fan mode got reset though. Does that get killed on a firmware update?

AH0U

Mark I watched your videos and notice you used your power setting to around 40 on the scale .. whatever that means... I duplicated your test and get about the same numbers except where you ran the TUNE slider to around 40 to get 1000 out, I have to run mine to max and then it get only about 900 watts... I just it back from Flex and they swear it is perfect and works as any other PGXL... beats me

AH0U

Mike...Looking at your examples and trying to duplicate them , to get the same power you show, my Id is substantially higher than yours.. where you show around 25, mine is a little over 40 with MeFFA turned on and with a much lower SWR of around 1.2