Posts Tagged ‘Trouble shooting’

Some radical thinking

Do we need those inline fuses between our radio and power supply, most if not all radios come with them but are they always needed? There was a time when I thought the more fusing the better and safer, but does it add to the safety or is it just redundant fusing? First off let me begin with, this is my own opinion and I do follow it whether you choose to or not it is absolutely up to you. 

I was having an issue with my Icom 7610 cycling off and then back on again while transmitting . The issue was narrowed down to resistance within the cable from the power supply to the radio. I first replaced the poor terminal connections on my Astron power supply. The issue returned again it was then further determined that the guilty party was the inline fuse/fuse holder connection. I cut out both inline power cable fuses...OMG, you say?
Well, not really if (the big if) you have a power supply with very good built-in protection meaning over-voltage protection (crowbar), over-current protection (fold-back current protection), over-temperature shutdown and an internal AC fuse I believe you are good to go without inline DC fusing between power supply and your rig. Again in the background I hear "OMG, you did what"

If you don't need the inline protection then why is it there on most if not all rigs? The main reason is for mobile installations. The power supply is the car battery and there is no protection at the battery end for your rig. Also in the car, you have heat, cold, possible rodents,  moving parts and so on around your power cables to your rig. Compared to home installation with a quality power supply your  protection for a mobile installation is the inline fuses. 

I do hear some saying "Wait what if there is an issue in my supply line from the power supply to the rig" This is true BUT keep the power cable as short as possible and if you have worries about overheating cables, moving parts or rodents then you have bigger issues than un-fused power cables. Having said that if something between the power supply to the radio power cable causes a sudden increase in current or voltage the power supply protection will quickly look after that. 

 Some who have a large rig such as the Icom 7610 or other manufacturers could be saying "there is no way this rig will be used as a mobile by the average ham but it has fused leads". My answer to that is the big 5 (Icom, Kenwood, Yaesu, Flex and Elecraft)  have no idea what power supply you are going to use. Also, some may opt to use a deep cycle battery at home on a trickle charge or whatever. 

After everything I have said about fuses I am not against them and as a matter of fact I have a Rigrunner fused rail and use it and I am thankful for it. I connect my external ATU, noise cancelling unit and SWR meter (for the light) to it. 

Now if you have no issue with your supplied power to your radio and things are not acting up like they were with me then by all means keep the fused line but for me, some radical thinking cured the problem and some power supply understanding allows me to sleep at night knowing the radio is in good power supply hands.

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.

Issue with my feed line.

Troubling reading of coax 
Faulty PL259 

Last week I posted about a wonky SWR reading I was getting and I figured it may be the result of a loose PL259. The issue returned again but not as bad last week. Since moving my Endfed antenna to be able to extend the wire the coax was also moved and now has to be buried. I needed to place the coax in some PVC conduit and not direct buried underground. It was a nice day and I decided to place the coax in the PVC conduit. While I had the coax disconnected from the Endfed antenna to feed it through the PCV conduit I thought I would connect my Fluke multimeter to the coax. With both ends of the coax disconnected, I placed the multimeter leads across the centre and barrel of the PL259 just to make sure my reading was "OL" and low and behold it was not! 
Outdoor soldering station. 

As I wiggled and moved the PL259 the reading would rise and fall. Truth be told this PL259 was a plastic moulded factor installed connector that I was not too keen on but for some reason decided to leave it on. Just to confirm it was the PL259 I cut it off the coax and then retested the coax from the centre conductor to braid and the meter read "OL" Fortunately I just installed 120-volt outlets in my shed so it was a matter of running an extension cord from the shed to an outdoor soldering station I set up to solder in a new PL229 connector.

One of those “Are you kidding me” mommets.

Back in late April, I posted the inspection of two heat sinks my Icom 7610. I always get a bit anxious when I remove all the cable from the radio and all that is plugged into it. In the past, I have learned that it saves lots of time and headaches if I use my trusty iPhone and take pictures of the cabling. I really don't have all that many cables at the back of the radio BUT I still take pictures. Once the heat sinks checked out to be without issue it was time to re-connect the radio again along with my trusty pictures.
All was connected and it was time to fire up the radio and see what happened. Everything was good and now it was time to make sure all software was "talking" to the radio. There were no issues so far until I went into transmit. The antenna I am using is an EndFed multiband and I do need a tuner to allow a decent SWR. The odd thing was it seemed my tuner lost its memories of the presets for each band. That was no issue I just started back at square one and returned each band so it was in memory. The issue was after tuning the band I would attempt to transmit and the tuner would start tuning again as the SWR seemed to go back up over 3.0. The first thing I checked was that the antenna was still up and it was as you never know stuff happens. I double-checked the rear of the radio with my pictures and all was good there.
To me, it seemed something was up with either a coax patch cable or the coax out to the antenna. The first thing I wanted to check was the PL259 connectors on the back of the radio. I have in the past had these connectors show issues once they were moved around with being unconnected and re-connected. I try to keep coax angles very slight as I have found over time this can add stress to the connection. I was not looking forward to the whole process but it was the next step that had to be done.
I am not sure why but out of the corner of my eye I noticed my LDG DTS-4 antenna switch which I use as a radio switch (between my Icom 7610 and Elecraft KX3) and not antenna switch as I only have one antenna at the moment. The light on the DST-4 position 1 for my 7610 was out and the light for the KX3 position 4 was on! Problem solved the DTS-4 was grounding out my 7610 as it was not selected and with the simple push of a button my problem was solved.  

The Astron RS20-M repairs completed

Repaired and working
The repairs to the Astron RS-20M are complete and the power supply I am happy to say is back up and running. In the process of sourcing out the parts that I needed a reader of my blog gave me a glowing recommendation of Digi-Key Electronics. I am very glad that he gave me the heads up regarding this company. When I went to the site you have the option of chatting live with an agent if you have any questions. I took advantage of this several times as I wanted to make sure I was choosing the correct items. The order was placed with them and immediately I received a
Negative to case ground 
Confirmation email regarding the payment going through. Within an hour another email was sent informing me my items had been shipped along with a tracking number. My dealings with Digi-Key was outstanding, I had recently dealt with an Amateur radio store up  this way (when ordering my new Astron power supply). The only email I was sent informed me my order had been processed and that was it. I wondered if just the payment went through, if the order had been picked and or if the order had been shipped? I ended up calling them to see if it had been shipped I asked when I may expect it to arrive, so I would make sure I was home as it needed a signature. The person on the phone sounded very put out as it required them to do some digging. They did return to the phone informing me it had been shipped and should be here by Friday. When I asked for the tracking number I was told it was not store policy to give out this information?? The power supply ended up coming on Thursday, and I was not home which required me to make a trip to the post office on Friday to sign and pick it up. Let me get off my soapbox and get back to the power supply repairs.
I found this great site online regarding Astron power supply trouble shooting and repairs. This document really helped me with the trouble shooting and eventual repair of the power supply. There was another online article I came across regarding how Astron now and then has the negative terminal grounded to the case of the supply.
New bridge rectifier
The part that I had to replace was the Bridge rectifier but I also ordered some heat sink compound as this was used between the Astron case and bridge rectifier. I also removed the two pass transistors and replaced the heat sink compound there as well. As mentioned above some Astron power supplies have a wire going from the negative terminal to the case ground. I read the information (seem link above) regarding Astron sometimes grounding the negative terminal to the case of the power supply. My power supply was wired this way and I decided to remove this jumper wire, if you have the same situation with your Astron supply read the article via the provided link above and make your own decision.
With the new bridge rectifier installed and wires re-soldered, the pass transistors back in place and finally I did remove one connection of the Varistor to test it (tested ok) I had to also re-solder that back on as well. It was now time for the smoke test.......and I was pleased that no smoke was found and the power supply is now working without issue. I did connect it to the Icom 7610, adjusted the power to 50 watts and the power supply successfully passed the load test as well. This power supply is under sized for the Icom 7610, I now have a new Astron power supply that is sized correctly. I am now wondering if I should keep this supply or sell it?
Passed load test

WHAT an SWR of 99:9!!

The other evening I had an opportunity to get on the air it has just been to long and I was very excited about spinning the dial around the HF band! I ran the coax out to my MFJ 1788 on the balcony and fired up the K3. I jumped on 20m were not to much was happening but on 30m there was some Dutch DX that was calling CQ so I thought I would give them a go. Prior to calling my SWR on the loop antenna was tuned to 1.2:1 BUT when I started to call the Dutch station my SWR readout on the K3 magically became 99.9:1!!! It was like the coax had been removed from the antenna and was sitting on the ground. It was late so I wanted to look into this at a later time, this evening was the later time so I hooked the antenna up and gave 20m a go and the SWR once again on the K3 was showing 99.9:1. It was time to trouble shoot, was it the coax, MFJ 1788 antenna, the K3 or my LDG antenna switch? The first thing I wanted to do was to remove the antenna as the problem.
Without LDG antenna switch
I removed the coax from the antenna and in it's place put a 50 ohm dummy load. In a way I was relieved to see the 99.9:1 SWR thus removing the MFJ 1788 from the problem. Next I bypassed the LDG antenna switch and low and behold the SWR now was 1.1:1 and me saying thank god it was not my K3! So it would seem the LDG  antenna switch is the problem so I took the switch cover off and looked around. I cleaned the SO-239 connectors, check the internal connections and all seemed to be great. The only problem spot to me could be the switching relays with internal contact troubles? After exercising the relays the trouble in the LDG antenna switch seemed to be ok. If the trouble comes back this is a 4 position switch and I only use 2 positions I could swap out relays and look at ordering all new relays. At this point all seems to be working well but stay tuned to see if relay swapping and ordering is in the near future.
Relay in the LDG antenna switch

Water + PL-259 = no radio for the day!

The waterlogged  PL-259
Well FINALLY I was able to get some radio time it has been so long and really there were no good reasons just what I call excuses!  On Saturday afternoon it was time to get some long over due radio time in. I ran my coax jumper  to the 1788 MFJ loop from my K3 radio, I settled into my radio chair and flipped the switch…..and……it was time for Murphy to visit me! With the MFJ loop you are supposed to tune the loop for peak noise and this was just not happening. I was getting numerous peaks but the SWR was all over the place! I thought about it for some time and after trying numerous ideas it finally hit me! I have a 6 foot coax tail on the loop and via a coupling I connect the coax from indoors. It was really raining the last few days and the balcony was very wet and "normally" my outdoor coax tail is in a plastic zip lock bag. This past rain storm was also accompanied with a strong wind and somehow the coax was removed from the bag and was in the water. I removed the coax and checked it with my ohm meter and it showed a high resistance between the centre conductor and shield. So it seems water has made it's way into the PL-259 connector and after installing a new piece of coax and doing some check with great results it was time for bed. My loop is supported by the MFJ tripod. I have a cover over the loop it to help disguise it and kinda makes it look like patio furniture. There is lots of wind being high up and on the lake so the cover has to be secured around the centre pole of the tripod. It's great that the antenna works perfect with a cover and with it secured as well I just want to come up with an easy way to connect and disconnect the coax from the antenna. I don't want to remove the cover or un-secure it from the centre pole. Any ideas from ham world would be approbated.
A shot of the balcony antenna open for suggestions. 

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