Low Power Output on 6600

Andy M5ZAP

Hi I have owned my 6600M for almost a year now and since new it has only put out approx 80w. It is slightly band dependent some less than 80 sone slightly more. This is the same into either a dummy load or my aerial system. Test performed with tune level set to 100% and CW key down. Tested with and without the antenna tuner in circuit. My 6500 was 100w or slightly more with same test setup. Anybody else see low power output? Regards Andy M5ZAP

Paul - GI4FZD

What meter are you using?

paul

Gordon, ve7on

What is your input voltage when key down?

Mike-VA3MW

Hi Andy

Just about every low power issue we get is related to low voltage to the radio when under full power out.  

You will need to send full power out in tune mode and then use a voltmeter to measure the voltage at the back of the radio.  Not at the power supply.  

It should be greater than 13V.  

Also, you don't mention which power supply you are using.  It must be a 12V 25 Amp  supply.  A 20 Amp supply is not powerful enough as they only provide 16 amps on full load.

We need to eliminate voltage sagging as the problem

73, Mike va3mw

John KB4DU

Geoff AB6BT

80 Watts is less than 1dB below 100 Watts...

John KB4DU

True. Even 50 watts (1/2 power) is only 3dB, 1/2 S-unit. But it would be nice to get all the power paid for.

Andy M5ZAP

The internal flex meter. Which I presume is accurate

Andy M5ZAP

Hi Mike
It’s an Alinco DM-330mv. Rated at over 30A
I have already measured the voltage during the measurements and it remains well above 13v at the back of the radio.
I even positioned the power supply next to the radio and reduced the cable length to reduce the voltage drop across it. Andy M5ZAP

Andy M5ZAP

Hi John
I have already tweaked the voltage up to the top end of spec. Results were taken with that setting.

Andy M5ZAP

Geoff a very predictable reply. If you read my post I wasn’t asking how many dB down my output was I already knew that. But as John says the spec is 100w and it would be nice for the radio to perform to specification. That’s what I paid for!

Cal N3CAL

Paul - GI4FZD

anything set in here in the max power box, i never run my radios at full power. 

Mike-VA3MW

I used to have one of those power supplies, but I had to toss it out.  Make sure you AC ripple meets specs.  Mine did not and I didn't feel like replacing the capacitors.  

What is the AC ripple on full load?  You can measure that with a meter in AC mode while in TX.   It should be less than 15mv P-P under full load.

As well, mine got RF noisy.  Another reason to toss it sadly.

This might not be the answer, but it is something that may be contributing.  What we see at the moment is the symptom (low RF out).  Now we have to find the cause.

73

k3Tim

I'd pull the cover and check on the output side of the internal fuse.  Some have reported here needed to clean the contacts of the fuse holder and fuse.  Some have gone so far as to use conductive grease. 

Best of Luck...

_..--
Tim - k3Tim/7

Andy M5ZAP

Thanks Cal. I’ll repeat the tests using FRstack to determine actual in radio voltage to check drop across the connector. Interesting thing is that my 6500 put out 100w plus without any issues.

Andy M5ZAP

Thanks Tim I will check that.

Andy M5ZAP

I have also tested on a Samlex SEC 1225 with the same results.

I will however check for ripple but not sure why that would affect power output. What do Flex specify as acceptable ripple?

I have used two of the Alinco PSU and both have been RF quiet. As a matter of interest what power supply do you recommend.

Andy M5ZAP

No it’s not limited there.

Mike-VA3MW

That is good data.  

The fuse is the next thing to look at.  You will need an 8mm Torx driver to get to it.

We specify no ripple  (sort of).  The radio expects clean DC power.  It is up to the power supply to do the rest.  15mv is pretty good.

When you have AC ripple superimposed on DC, then your VOM won't read correctly since the AC  ripple will affect the reading.  

Mike

Andy M5ZAP

Have tried setting the voltage as reported by frstack to 14.4v at idle that gives 13.7v under load. No improvement

Using my uncalibrated DVM I get 60mv of AC ripple measured both on and off load.

I’m operating remote for next few days, I will test the Samlex supply ripple on my return.

You didn’t answer my question what is a good power supply.

Mike-VA3MW

Hi Andy

We don't test them at all, but we have sold Astron and Powerworx and both have been fine.  We have moved away from Astron, but only due to a supply issue.  

60mv is not an issue.  1000mv would be.  So, that isn't it.  

Like other have said, have a look at the fuse for corrosion.  There is a coating you can add, but I can't remember the name.  

If, after all that you still have a problem and the wattage you are getting is a concern, then you will likely have to send it to a service center.  

Sorry to make you  jump through hoops, but these are all good data points and help narrow down the problem and ensure it isn't the environment.

Mike

paul

Hi Mike, I ran various tests and different power supplies with vom probes inserted  into Anderson  connector on  back of Flex. I unplugged   power pole connectors in the system from astron and  Samlex  power supoly  and voltage came up  under load. End result was Anderson power poles  do not  make a  gud connection after  time under high current. So maybe disconnect and  re connect to make a  good  connection also look  at the power pole from the end and make sure the connector overlaps  the  output.gl, paul, wa3qpx

John KB4DU

Mike;

Two opinions ( like belly buttons, everybody has one):

Not necessarily your case, but some of the PowerPole components being sold are CCI (cheap Chinese imports), which may not be up to the job.

Also, getting into the area of religion, I have several of the MFJ 4230 power supplies in use (my rig, wife's rig, son's rig, Fire Dept radios) and they have worked very well for me. The voltage adjustment knob is on the front along with the meter, makes the adjustment easy. Also, I like having the power connections on the back, out of sight. No discernible noise from the PS on any of the rigs. And the price is right. So is the weight and size.  YMMV. Nomex on.

John KB4DU

Mike;

Two opinions ( like belly buttons, everybody has one):

Not necessarily your case, but some of the PowerPole components being sold are CCI (cheap Chinese imports), which may not be up to the job.

Also, getting into the area of religion, I have several of the MFJ 4230 power supplies in use (my rig, wife's rig, son's rig, Fire Dept radios) and they have worked very well for me. The voltage adjustment knob is on the front along with the meter, makes the adjustment easy. Also, I like having the power connections on the back, out of sight. No discernible noise from the PS on any of the rigs. And the price is right. So is the weight and size.  YMMV. Nomex on.

David Decoons, wo2x

I always run DC cable from power supply binding posts straight to the radio. I have a West Mountain Radio 4008 RigRunner and have found too much voltage drop going through that to the radio. I only use the RigRunner for low current accessories.

The voltage drop across Anderson Power Poles (and the knock offs) can be a real issue under full power.

The Flex API allows seeing voltage at input to the radio as well as at the PA (after the internal blade fuse). This allows me to use Node Red to see if there are connection issues.

my friend had a similar low power/large voltage drop issue on the 6500 I sold him. His solution was to use a very this film of silver conductive grease on the metal portions of the Power Pole connectors and the blades of the fuse. It made a significant improvement. With the silver conductive grease, less is better. You only want a very light film of it on the connections.

73 Dave wo2x

AG4Q

I noticed my 6600 TX power seemed to be topping out at 80 watts. Then one day last week I noticed the TX power abruptly changing on key down. I noticed the power supply volt meter was steady, but the current was jumping around. Long story short: I unplugged and reinserted the 30A fuse inside the radio a few times. Now the power out is steady at 100 Watts again. I've only had the radio for 5 months, so I hope this is not a reoccurring problem. The fuse is not easy to access.