What is the cause (and fix) of a significant output power loss in my 6500 running v2.1.32?

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  • Updated 4 months ago
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This problem began yesterday when I was on 30m with the ATU bypass on (1.2:1 SWR).  When I switched to 40 meters the power remained low.  At the 10watt setting I'm seeing 400 mills output and at the 100 watt setting I'm seeing about 20 watts output.  The power loss persists into good antennas across many bands (15,20,30,40 and 80).  Sounds like a bad final or driver to me.
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Joe - N7IV

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Posted 4 months ago

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Bill -VA3WTB

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I would consider a cold reset, shut down and un plug power cable for a minut, then restart. If that does not work, do a factory re set,,save you profiles.
Just make sure the max power setting has not changed in radio set up first.
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Bob Gerzoff, WK2Y

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Supply voltage ok?
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Jim Gilliam

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Always have a dummy load on hand to eliminate any antenna or tuner issues.


Jim, K6QE

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KF4HR

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Joe - I've been noticing something similar with my 6700 lately (low power).  I found that if I switch the Mic input selection to BAL (or something else other than MIC), then switch it back to MIC, full power returns.  This issue doesn't surface all the time, just occasionally.
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WX7Y

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Hi Joe, 
with a good volt meter check the voltage right at the back of the radio's Power-Pole connectors WHILE TRANSMITTING. 

With power Pole connectors some times they get bent a little bit and loose there contact pressure agents one another and just require a little tweak to bend the contacts out a little bit.
Also use ONLY 45AMP Power pole connectors (these still fit the same shell) and solder the wires after there crimped if you install them on the ends of the cables or build your own Power cables.

You also want the shortest length and largest gauge wire that will fit the Power Pole connector shells on the Power Cables between the radio and Power supply,  Your Power Supply should have enough current to handle the FLEX radio's current draw and be adjusted for 13.8 to 14.2 Volts. (13.8) @ the Radio and full Power Transmit works the best. 

73
Bret
WX7Y
(Edited)
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Bob Gerzoff, WK2Y

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I have a relatively long run from my power supply to my rig.  I just got a little inline voltage monitor and keep it at the rig.  Very handy.  Found that the using some deoxit on my powepole connects gained me 0.6 volts at the rig.  I'm still dropping down a good 1 to 1.25 under transmit so I need to up the gauge of my wire and connectors.  Wouldn't have known if I hadn't put the monitor in. 
73,
Bob, WK2Y
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Bill -VA3WTB

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You will not hurt anything by doing a factory reset, this needs to be done in order to trouble shoot your problem.
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Joe - N7IV

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Yup.  I saved the profiles and did the factory reset.
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Joe - N7IV

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Thanks for the prompt reply and suggestions. Bill, I did a cold reboot (disconnecting power).  No change.  I'll reserve the factory reset for a last resort;  Bob I've been watching the powers supply voltage for about a half an hour under both key-up and key down conditions.  It's rock solid;  Jim, I retook the readings bypassing the tuner with a dummy load and my old Bird.  Same deal max about 20 watts across bands; KF4HR, I bumped the mic/balance selector a few times, no joy.  I'd really like to get this fixed without having to mail the rig back to Texas.  This was really bad timing as the ARRL CW contest is one of my favorites.
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Tim - W4TME, Customer Experience Manager

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Whenever we have reports of this, we have the user check the voltage at the radio as has been suggested above.

Then we have the user create a power curve by doing the following:

1.) Export a complete set of your profile data as a backup
2.) Do a factory reset of the radio to clear any band persistence data
3,) Connect the radio to a dummy load capable of handling 100W
4.) Tune Slice A to the middle of the 160m band
5.) Click on the TUNE button and move the TUNE POWER slider up to 100 - record the output power level
6.) Move the TUNE POWER slider down to 10
7.) Click TUNE to stop the radio from transmitting RF
8.) Tune Slice A to the center of the 80m band
9.) Repeat steps 5-7 to get the power curve data for the 80 band

Do this for 160, 80, 40, 30, 20, 17, 15, 12, and 10m bands.  

You should get 100W nominal out on all bands.  If you are getting really low power (10s of watts), then there is a hardware issue that needs to be addressed via the HelpDesk.
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Joe - N7IV

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Will do Tim.  I'll let you know how it works out.
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Joe - N7IV

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Ok Tim,  here's the power curve for my 6500 s/n 6500-1576:
1.9 MHz @ 10 w :  4 w out; @ 100 w: 13 w out
3.750 MHz @ 10 w : 1 w out; @ 100 w: 15 w out
5.3585 MHz @ 10 w : 600 mills out; @ 100 w: 16 w out
7.125 MHz @ 10 w : 300 mills out; @ 100 w: 17 w out
10.125 MHz @ 10 w : 100 mills out; @ 100 w: 27 w out
14.175 MHz @ 10 w :  < 100 mills out; @ 100 w: 18 w out
18.115 MHz @ 10 w : 100 mills out; @ 100 w: 15 w out
21.225 MHz @ 10 w : 100 mills out; @ 100 w: 15.5 w out
24.940 MHz @ 10 w : 200 mills out; @ 100 w: 19 w out
28.985 MHz @ 10 w : 400 mills out; @ 100 w: 28 w out
52.000 MHz @ 10 w : 500 mills out; @ 100 w: 14 w out
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Tim - W4TME, Customer Experience Manager

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That isn't good at all. Open a HelpDesk ticket so we can get you an RMA to resolve this issue.
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Joe - N7IV

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Done, and thanks.  Now I'll blow the dust off of my old National NCX-5 and run a vintage rig in the contest (if smoke doesn't come out).
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Joe - N7IV

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Thanks again guys, I'll keep at it as the suggestions come in;  Bob and Bret, I took another look at the power situation.  I don't have an in-line at-the-rig meter but I do have a soldered high-corrent power pole on a short (4') run of 12 AWG wire. By the way, the power supply is an Astron 35A.  The whole power system for the 6500 and the Maestro has been operating flawlessly since the rig was installed almost two years ago.  I took out the power pole and stuck it back in.  That's the first time it's been unplugged since I put the rig on the air.  Still no joy.
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Rick Hadley - W0FG

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You might download 'Flex Mete'...sorry, I don't have the link right at hand.  It will give you a reading of the voltage at both the radio PA and CPU.  DDutil will also track the voltage at the input to the radio.
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John - WA7UAR

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Do you mean this link Rick? http://www.denzone.com
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Joe - N7IV

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Rick and John,  I'll download the meter after the contest.
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Tim - W4TME, Customer Experience Manager

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The radio ended up being set in for service.

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