Monday, September 5, 2022

A little resistance goes a long way!


 This past weekend I was rolling along in the CWop open CW contest when all of a sudden when I sent CW my Icom 7610 shut down and then cycled back on all on its own. My output power was 100 watts and each time I transmitted the rig would cycle off and back on again. I had already been contesting for about 3 hours and all was good and now this!

As I sat there a thought occurred to me, in one of my Icom email groups I remember reading regarding this same issue. Those who had this issue found it was the Anderson power poles they were using. My rig goes to a Rig runner power bar using Anderson power poles and the power supply feeds the Rig runner via Anderson power poles. At this time in the game, I just wanted a fast fix so I powered the radio down and turned off the power supply. I then unplugged and plugged back in the Anderson power pole connectors and this did the trick for now. 

With the contest completed and still hearing CW rings in my ear, it was now time to turn my attention back to the 7610 power cycling issue. I subscribe to which is an email group and one of my email groups is called Icom 7610 you guessed it, it's all about the Icom 7610. I read the threads regarding power cycling and the Anderson power pole. The consensus seemed to be the connection point of these connectors can develop a poor connection. The fix some used was like I did to connect and reconnect a few times. While others removed that style of connector altogether. 

On the Icom touch screen, you can bring up a menu called meters. One of the meters is the Vd. This meter reads the real-time internal voltage of the 7610. On the scale, there is a red section and if the voltage gets to this point the radio will shut down. Once the sufficient voltage is supplied again the radio will cycle on again. Thus the issue I was having. When I was transmitting I was drawing much more current then bring in a poor connection (resistance) thus drawing more current. When you draw more current your voltage goes down and if it goes below what the Icom 7610 wants the radio shuts down. As soon as it shuts down more than enough voltage is available as very little current is being used and the radio cycles back on again. 

On the Anderson power pole site, they do have a bulletin as to why a connection issue may exist. Some causes they mentioned were a poor crimp connection if you decided to solder the connection a poor solder job and if the solder flowed down onto the connection tabs this could be an issue as well. I have to be honest I have been using Anderson power poles for a long time and I have never had an issue. 

I wanted to see if the Anderson power poles have in my case become an issue. My test was set up as follows. I wanted to have a steady constant load on the Icom 7610 and what better way than to transmit an FT8 tune signal, I choose to use 100 watts. I would connect the radio as it was during the contest and then send an FT8 carrier at 100 watts. Record the voltage drop on the Icom Vd meter. Then remove the Anderson power poles from the Rig runner. One is the power cord from the radio, the other from the power supply to the Rig runner. Run the same test and record the results. finally, remove the Anderson power poles from the cable from the Icom and connect it directly to the Astron SS-30-M power supply which has screw terminals. Then record the results. 

Before I began I checked the terminal voltage on the Astron power supply and it was 13.8 volts DC. Also during the tests, the power supply voltage stayed at 13.8 volts DC. Below are the results from the tests. 

Just a word about the Vd meter before we begin. I determined that the Vd meter scale is 0.24 volts per hatch mark. Therefore the minimum voltage red trip line on the Vd meter scale is the 6th hatch mark from left to right (11.44 volts) with the first hatch mark counted as zero. 

The first test was with the radio connected to the Rig runner via the Aderson power pole and the power supply connected to the Rig runner via the Anderson power pole. The results below when FT8 test tune at 100 watts was Vd voltage dropped to two hatch marks above the trip red line. 

For the second test, I removed the Rig runner and connected the two Anderson power poles one to the other. The FT8 100-watt test tune gave the same results,  two hatch marks from the trip red line. 


Finally, I removed the Anderson power pole from the radio power cord and stripped the ends and attached it directly to the Astron power supply via its screw connectors. The FT8 100 watts test resulted in a surprising result of 5 hatch marks above the red trip line. 

Removing the Anderson power poles from the circuit seemed to give some impressive results and I am going to leave it this way. If I need to use the Rig runner power bar I can power it from a spare Astron 25 amp supply I have. Once I have some spare time I am going to take the pair of Anderson power pole connectors apart and see if I can find what did possibly wrong.


John AE5X said...

Pretty interesting, Mike. It looks like you were losing close to 15 watts across that resistive connection (.75V difference X ~18 amps on transmit) - all dissipated as heat. I wonder if something like DeOxit would help with the connections and allow you to still have the benefit/convenience of your power strip.

John AE5X

VE9KK said...

Good morning John and very nice to hear from you hope you are enjoying your new State and retirement. Interesting is a very good way to describe it for sure. At this point in time am going to leave the Rig runner out of the picture. I have no extras that need the Rig runner power strip. I was surprised the Anderson power poles were the issue. I was thinking it was going to turn out to be the Rig runner but not so.
73 and have a great week,

MadDogMcQ said...

Interesting. I use Anderson PowerPoles almost exclusively and have never experienced any problems but then I don't use high power. Your post did remind me though of a 761-Resetting issue that my friend had and we tracked it down to his PSU. I think Icoms are quite sensitive to variations in voltage and current - for good reasons though.

I have also experienced resetting of TWO IC-7100s which occurred when the volume peaked too high. Weird!

Anyway, glad you sorted it out. Like the new blog :-)

73, Tom, M7MCQ

VE9KK said...

Good afternoon Tom very nice to hear from you, this was the first time I have ever had issues with the power poles. As you said the 7610 is a bit sensitive when it comes to the proper voltage. In the past when in a condo and townhouse I was always QRP. In that case, as you have found as well with low power most likely nothing would happen as you are not drawing a lot of current.