Topics

6700 Low Voltage lockup

Al Ludwick / NN4ZZ
 
Edited

Curious if anyone else has seen this.  My 6700 is 6+ years old and recently started locking up occasionally while transmitting ( CW ) with a voltage error on the front panel.  It was only once every week or two but has gotten worse lately.   Here is the error message:

13v8 - 9.44 volts
Check Fuse

I'm using a linear Astron RS-35M supply and heavy 10 gauge cables to the radio.  The voltage at the rear of the supply was 13.8V and at the radio read slightly lower at about 13.7V. 

Using the K9DUR SDRMonitor, the readings were 13.3V on RX and 12.7V on TX at 90W on the radio side of the fuse.   So the drop between what is supplied at the powerpoles and what the SDRMonitor reads was .4V on RX and 1.0V on TX.   Another way to describe it is the drop between RX and TX was an additional .6V.  These drops seems a bit high to me but may be normal.  

I did a few things: 
  • First I opened the radio case and looked at the 30A fuse.  It had some brown oxide on the legs so I cleaned them off. 
  • I opened the Astron RS-35M and adjusted the voltage up to 14.4 Volts which reads about 14.3 at the radio. 
  • The SDRMonitor now reads 14.0V on RX and 13.7 on TX.   The drop between RX and TX is now only an additional .3V   So improvements in all cases.
So far the problem has not recurred but I need more testing time to be sure.  It seems like the dirty fuse was at least part of the problem.  Could be that the oxide was responsible for the drop and maybe gets worse when the key is down for a while.  The SDRMonitor might not catch a lower reading (like the 9.44V reported on the front panel) since the radio locks up and can't update the monitor.  Increasing the power supply voltage probably helps also.  BTW, if anyone needs the steps to adjust the Astron RS-35M supply voltage I found a good document on it by W1MIK.  

http://www.repeater-builder.com/astron/voltage-adjust/voltage-adjust.html

So if you have seen this problem or have any feedback on the notes above, let me know.  

Regards,  Al / NN4ZZ  
al (at) nn4zz (dot) com






Ray Andrews
 

Al,

I have seen this a couple of times. Most recently during the NAQP-CW contest this past Saturday.  When it occurred, SDRMonitor was reporting a voltage of 9.36 VDC.  It took a couple of reboots of the radio to clear the issue.

73, Ray, K9DUR


On Jan 14, 2019, at 4:28 PM, Al Ludwick / NN4ZZ <al@...> wrote:

Curious if anyone else has seen this.  My 6700 is 6+ years old and recently started locking up occasionally while transmitting ( CW ) with a voltage error on the front panel.  It was only once every week or two but has gotten worse lately.   Here is the error message:

13v8 - 9.44 volts
Check Fuse

I'm using a linear Astron RS-35M supply and heavy 10 gauge cables to the radio.  The voltage at the rear of the supply was 13.8V and at the radio read slightly lower at about 13.7V. 

Using the K9DUR SDRMonitor, the readings were 13.3V on RX and 12.7V on TX at 90W on the radio side of the fuse.   So the drop was .4V on RX and 1.0V on TX.   This seems a bit high to me but may be normal.  

I did a few things: 
  • First I opened the radio case and looked at the 30A fuse.  It had some brown oxide on the legs so I cleaned them off. 
  • I opened the Astron RS-35M and adjusted the voltage up to 14.4 Volts which reads about 14.3 at the radio. 
  • The SDRMonitor now reads 14.0V on RX and 13.7 on TX.   The drop is now less at .3V on RX and .6 on TX.  
So far the problem has not recurred but I need more testing time to be sure.  It seems like the dirty fuse was at least part of the problem.  Could be that the oxide was responsible for the drop and maybe gets worse when the key is down for a while.  The SDRMonitor might not catch a lower reading (like the 9.44V reported on the front panel) since the radio locks up and can't update the monitor.  Increasing the power supply voltage probably helps also.  BTW, if anyone needs the steps to adjust the Astron RS-35M supply voltage I found a good document on it by W1MIK.  

http://www.repeater-builder.com/astron/voltage-adjust/voltage-adjust.html

So if you have seen this problem or have any feedback on the notes above, let me know.  

Regards,  Al / NN4ZZ  
al (at) nn4zz (dot) com








Bill Barrett
 

Hello Al-
Needed to change out a fan recently, after replacement reconnected everything to the radio and started it up. After a few seconds received the message you mentioned.
Tried to restart the radio two times but received the voltage error. Disconnected the power wires and plugged them back in, problem went away.
Radio has been fine for a week now. 
I have replaced 3 fans so far. The originals lasted just over the warranty period. They seem okay when connected to 12V but after a while they start to vibrate and slow down.
Have one more replacement and 4 new ones coming from Eric. "Just in time"!!

Bill W2PKY 

On Mon, Jan 14, 2019 at 4:29 PM Al Ludwick / NN4ZZ <al@...> wrote:
Curious if anyone else has seen this.  My 6700 is 6+ years old and recently started locking up occasionally while transmitting ( CW ) with a voltage error on the front panel.  It was only once every week or two but has gotten worse lately.   Here is the error message:

13v8 - 9.44 volts
Check Fuse

I'm using a linear Astron RS-35M supply and heavy 10 gauge cables to the radio.  The voltage at the rear of the supply was 13.8V and at the radio read slightly lower at about 13.7V. 

Using the K9DUR SDRMonitor, the readings were 13.3V on RX and 12.7V on TX at 90W on the radio side of the fuse.   So the drop was .4V on RX and 1.0V on TX.   This seems a bit high to me but may be normal.  

I did a few things: 
  • First I opened the radio case and looked at the 30A fuse.  It had some brown oxide on the legs so I cleaned them off. 
  • I opened the Astron RS-35M and adjusted the voltage up to 14.4 Volts which reads about 14.3 at the radio. 
  • The SDRMonitor now reads 14.0V on RX and 13.7 on TX.   The drop is now less at .3V on RX and .6 on TX.  
So far the problem has not recurred but I need more testing time to be sure.  It seems like the dirty fuse was at least part of the problem.  Could be that the oxide was responsible for the drop and maybe gets worse when the key is down for a while.  The SDRMonitor might not catch a lower reading (like the 9.44V reported on the front panel) since the radio locks up and can't update the monitor.  Increasing the power supply voltage probably helps also.  BTW, if anyone needs the steps to adjust the Astron RS-35M supply voltage I found a good document on it by W1MIK.  

http://www.repeater-builder.com/astron/voltage-adjust/voltage-adjust.html

So if you have seen this problem or have any feedback on the notes above, let me know.  

Regards,  Al / NN4ZZ  
al (at) nn4zz (dot) com










--
Bill Barrett
352-437-4758

Al Ludwick / NN4ZZ
 

Hi Ray, 
Thanks, I guess whether your SDRMonitor catches the lower voltage just depends on the polling.  And IF it catches the lower voltage befor the radio crashes.  Thanks again for a good tool to monitor the voltage and temp.  It is one of just a few third party apps I run. 

HI Bill,
As you noted, I think the powerpole connection is another place where a loose or poor connection due to buildup can be a problem.  I’ve been lucky with the fans so far but I’ve got spares just in case. 

Regards Al / NN4ZZ

Bret Mills
 

Sounds like it might be a good idea to put a tiny dab of NO-OX on all the Anderson connectors and fuse holder after cleaning them of course when I open the case again or have to pull the plug.
73's and tnx for the heads up gents.
Bret
WX7Y


On Mon, Jan 14, 2019 at 3:22 PM Bill Barrett <billbarrett174@...> wrote:
Hello Al-
Needed to change out a fan recently, after replacement reconnected everything to the radio and started it up. After a few seconds received the message you mentioned.
Tried to restart the radio two times but received the voltage error. Disconnected the power wires and plugged them back in, problem went away.
Radio has been fine for a week now. 
I have replaced 3 fans so far. The originals lasted just over the warranty period. They seem okay when connected to 12V but after a while they start to vibrate and slow down.
Have one more replacement and 4 new ones coming from Eric. "Just in time"!!

Bill W2PKY 

On Mon, Jan 14, 2019 at 4:29 PM Al Ludwick / NN4ZZ <al@...> wrote:
Curious if anyone else has seen this.  My 6700 is 6+ years old and recently started locking up occasionally while transmitting ( CW ) with a voltage error on the front panel.  It was only once every week or two but has gotten worse lately.   Here is the error message:

13v8 - 9.44 volts
Check Fuse

I'm using a linear Astron RS-35M supply and heavy 10 gauge cables to the radio.  The voltage at the rear of the supply was 13.8V and at the radio read slightly lower at about 13.7V. 

Using the K9DUR SDRMonitor, the readings were 13.3V on RX and 12.7V on TX at 90W on the radio side of the fuse.   So the drop was .4V on RX and 1.0V on TX.   This seems a bit high to me but may be normal.  

I did a few things: 
  • First I opened the radio case and looked at the 30A fuse.  It had some brown oxide on the legs so I cleaned them off. 
  • I opened the Astron RS-35M and adjusted the voltage up to 14.4 Volts which reads about 14.3 at the radio. 
  • The SDRMonitor now reads 14.0V on RX and 13.7 on TX.   The drop is now less at .3V on RX and .6 on TX.  
So far the problem has not recurred but I need more testing time to be sure.  It seems like the dirty fuse was at least part of the problem.  Could be that the oxide was responsible for the drop and maybe gets worse when the key is down for a while.  The SDRMonitor might not catch a lower reading (like the 9.44V reported on the front panel) since the radio locks up and can't update the monitor.  Increasing the power supply voltage probably helps also.  BTW, if anyone needs the steps to adjust the Astron RS-35M supply voltage I found a good document on it by W1MIK.  

http://www.repeater-builder.com/astron/voltage-adjust/voltage-adjust.html

So if you have seen this problem or have any feedback on the notes above, let me know.  

Regards,  Al / NN4ZZ  
al (at) nn4zz (dot) com










--
Bill Barrett
352-437-4758

Al Ludwick / NN4ZZ
 
Edited

David Siddall
 

One can buy Noalox at Home Depot, Lowe's, etc.  I use it on all antennas.

Dave K3ZJ

On Tue, Jan 15, 2019 at 12:55 AM Al Ludwick / NN4ZZ <al@...> wrote:

[Edited Message Follows]

Hi Bret,
The NO OX sounds like a good idea.  Found it on Amazon.

https://www.amazon.com/dp/B00HSW341A/?coliid=I8YU5OKDU5EKY&colid=29GZE04YWQV9V&psc=0&ref_=lv_ov_lig_dp_it


Another product that looks good:

https://www.amazon.com/MG-Chemicals-Conductive-conductivity-Dispenser/dp/B005T8QLYM/ref=sr_1_3?ie=UTF8&qid=1547473675&sr=8-3&keywords=conductive+silver+grease


Thanks, Al / NN4ZZ

Mike Pappas
 

This is what happens when you get a bit of corrosion on a fuse holder thats running 8 amps continuous on a Whelen Edge 9000 strobe power supply..  

We couldn’t figure out why the back strobes were out…

And it was a project swapping it out with the spare.

It got happy with a new fuse holder and a shot of lithium grease on the contacts.

Mike Pappas
W9CN
303-988-0976
advanceddigital@...



On Jan 15, 2019, at 5:58 AM, David Siddall <hhamwv@...> wrote:

One can buy Noalox at Home Depot, Lowe's, etc.  I use it on all antennas.

Dave K3ZJ

Al Ludwick / NN4ZZ
 

Hi Dave,
It looks like Noalox is intended for aluminum connections....not sure if that is correct or a problem.





This other product seems to be for dissimilar metals as well.  And uses SILVER to help conductivity.  Do you think it would be a better choice?





Regards,  Al / NN4ZZ  
al (at) nn4zz (dot) com

David Siddall
 

Since it is used by electricians in dissimilar metal situations (copper/aluminum), I would think that it would be OK 
between any, since these two are pretty far apart on the galvanic tables.  The "gold standard" today, at least for 
use on galvanized towers and aluminum antennas, actually is copper-based: Jet-Lube SS-30.

73, Dave K3ZJ

On Tue, Jan 15, 2019 at 8:14 AM Al Ludwick / NN4ZZ <al@...> wrote:
Hi Dave,
It looks like Noalox is intended for aluminum connections....not sure if that is correct or a problem.





This other product seems to be for dissimilar metals as well.  And uses SILVER to help conductivity.  Do you think it would be a better choice?





Regards,  Al / NN4ZZ  
al (at) nn4zz (dot) com

Al Ludwick / NN4ZZ
 

Thanks Dave,
The Jet-Lube SS-30 Looks very good and gets great reviews on Amazon.  It seems like it or the MG product with Silver would be excellent, good conductors and anti-oxidants.  I'm going to order one of them to try it on the powerpole connections and the fuse next time I open the radio.

Regards,  Al / NN4ZZ  
al (at) nn4zz (dot) com



Brian Davis
 

I just went thru this same issue with my 6500. I run the 6500 remote most of the time so for a while I missed the front panel error message. I thought I had an internet connectivity problem. To make a long diagnosis short. the problem turned out to be be a bad or intermittent power supply. I use an Astron 20 amp power supply dedicated to the Flex (so I can remotely turn it on and off). Finally I got around to putting the p/s on the bench and put a nice load on it by using a 12v to 120V AC inverter. I let that inverter power a 200 watt lamp for a while and the trouble appeared. One pass transistor was not warm and the voltage regulation was poor. With no load the voltage is OK. A jumper buss wire to one transistor had come loose due to solder fatigue. Astron simply tack-soldered the buss wire to the transistor socket and the heat cycling caused the failure. BTW...I identified the bad power supply by swapping in another power supply and the failures disappeared. Brian W9HLQ

Brian Davis
 

Follow up on my low voltage lockup due to flaky power supply.

I use an Astron RS-20 amp supply for my Flex6500.  I started getting lockups on the Flex and found it was due to a weak power supply.  This model has two pass transistors.   When I put the supply on the bench it would only fail under load since one transistor was dead and one transistor was still working...sort of.   I concentrated trouble shooting on the wiring around the non-working and cold transistor.  I found a hairline crack in the solder to the socket.  Using my solder gun and reflowing the connection with some fresh solder, the problem went away.  Pictures hopefully will be included below.

For you power supply fans:   I adjusted the repaired power supply for 13.5 volts.  As you can see, going to full load of almost 20 amps caused the terminal voltage to drop only 0.02 volts.   That is good regulation.  However by the time the DC gets to the Flex thru the Power Poles, the voltage drops almost 0.5 volts when tuning at 100 watts.  The heat sink gets quite warm.  Mine peaked at 125 degrees in a cool basement.   A call to the Astron factory informed me that the heat sink running at 150 degrees is acceptable. 

Astron makes a good power supply for the money.

End of red line shows hairline crack in solder at the socket.


Full load and only 0.02 volt drop

Heat sink gets quite warm at over 120 degrees

73,
     -=Brian, W9HLQ=-

Al Ludwick / NN4ZZ
 

UPDATE -- No more voltage lockups.  It was happening at least once or twice per day at it's worst lately.  I also applied the MG Silver Conductive Grease to the powerpoles on the radio today as an extra measure.   Next time I open the radio, I'll add the MG grease to the fuse.  

Voltage is holding steady -  The SDRMonitor now reads 14.0V on RX and 13.7 on TX. 

Cleaning the fuse was probably the main issue.  But adjusting up the power supply up from 13.8V to 14.4V probably helps too although it worked fine at 13.8V for years.  

If you have a need to open your radio up for some reason, it would be a good idea to take a look at the fuse and clean it up as a precaution.  And if you have the conductive / anti-oxidant grease, add it too.

Regards,  Al / NN4ZZ  
al (at) nn4zz (dot) com

Andrew Russell
 

https://www.andersonpower.com/content/dam/app/site/resources/techreference/app_pm.pdf

 

Anderson’s recommendations.

 

Andrew VK5CV

 

Sent from Mail for Windows 10

 


From: FlexRadioSmartSDR@groups.io <FlexRadioSmartSDR@groups.io> on behalf of Al Ludwick / NN4ZZ <al@...>
Sent: Thursday, January 17, 2019 7:55:59 AM
To: FlexRadioSmartSDR@groups.io
Subject: Re: [FlexRadioSmartSDR] 6700 Low Voltage lockup
 
UPDATE -- No more voltage lockups.  It was happening at least once or twice per day at it's worst lately.  I also applied the MG Silver Conductive Grease to the powerpoles on the radio today as an extra measure.   Next time I open the radio, I'll add the MG grease to the fuse.  

Voltage is holding steady -  The SDRMonitor now reads 14.0V on RX and 13.7 on TX. 

Cleaning the fuse was probably the main issue.  But adjusting up the power supply up from 13.8V to 14.4V probably helps too although it worked fine at 13.8V for years.  

If you have a need to open your radio up for some reason, it would be a good idea to take a look at the fuse and clean it up as a precaution.  And if you have the conductive / anti-oxidant grease, add it too.

Regards,  Al / NN4ZZ  
al (at) nn4zz (dot) com

Al Ludwick / NN4ZZ
 

Hi Andrew,
Thanks for the link.  Good info. 

It sounds like the powerpoles  "self clean" when connected and disconnected.  At least in my case, the power was left connected for years, so that may allow some oxide buildup.   The MG Silver Conductive grease sounds like the lithium grease but also conductive ( with the silver) and an antioxidant.  It is probably overkill and more expensive but since I got it for the fuse....    I have a number of other powerpole connectors in use around the shack that have been connected for years and I've never applied any lubricant so will have to keep that in mind if any issues arise.  

From Andrew's link and the powerpole documentation:

1. Dirty Connectors - When engaged and disengaged, the contact surfaces of Anderson SB® Connectors “over wipe,” thus providing a self cleaning action. To ensure the continued benefit of this feature, clean the contact surfaces and lubricate the connector. Use a “white” lithium grease, which may be obtained from hardware stores and automotive parts suppliers.

Regards,  Al / NN4ZZ  
al (at) nn4zz (dot) com

Al Ludwick / NN4ZZ
 

Feb 4 Update -- 3 weeks now and no more "Low Voltage" lockups.  

I posted some new notes and pics on my 6700 web page showing the voltage measurements before and after the main fuse.   And some tips on one way to measure the voltage at the powerpoles on the radio when it is still connected.   That allows you to get readings before and after the fuse at the same time  for either RX or TX and determine if the issue is in the radio or in the power supply. 

http://nn4zz.com/FLEX6700.htm?#Low_Voltage_Lockup

Thanks again to Ray K9DUR for the SDRMonitor.  It was also very helpful to see the error message on the front panel of the 6700.  Only the 6500 and 6700 have the front panels.  Without the message it would have been difficult to know the initial reason the radio locked up.   The panel is especially helpful since RFI intrusion is another common cause of lockups with some similar results.  Hopefully these notes will be helpful to others who experience the lockup and to consider the low voltage problem as a potential cause. 

Regards,  Al / NN4ZZ  
al (at) nn4zz (dot) com