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.
6 comments:
Hello Mike, in case of a well protected PS it is certainly a consideration. But you have to be 100% shure it is protected like that. I'm not shure my Astron RS50A lineair PS does have all those protections, although the DXengineering site says it does. So just to be shure I keep my fuses inline.
The only thing I want to do is shorten the supply wires. 73, Bas
Good morning Bas and very nice to hear from you, I contacted Astron regarding my power supply and I was assured it did have all the protection that was listed on the website. In the reading I have been doing when there was an issue it was the well protected power supply that shut things down before the inline fuses saw anything. As you say it is just an added line of protection is you feel better about having the inline fuses in the circuit.
Have a good week Bas and good luck with the 6m adventures I am enjoying reading about your contacts.
73,
Mike
VE9KK
Mike: In your scenario you have confidence that the protective functions in your PS will protect your rig. Great!
I'm in the process of converting to battery power in the shack, with a big (200 AH) LiFePO4 battery charged by solar panels. Those batteries have a huge fault current capacity. I will definitely have a fuse as close to the battery as possible.
73
Dave, VE3WI
Good morning Dave, for sure in your case make sure the rig is protected. As you said the the fault current on a battery is huge. As stated in my post if your power source is something other than a known fully protected power supply then yes fusing and any other protection is in order.
73,
Mike
VE9KK
Hi Mike, hope you're well.
I don't have fuses on my transceivers at home in the shack either. What's the point when the PSU has the protection? The inline fuse-holders are just more stuff to snag when you're trying to remove a radio from its spot. They're better thank grappling hooks LOL
PS: Did you see the video on W2LJ's blog about that young chap learning CW just for the heck of it?
https://youtu.be/q6c3h31rjag
73, Tom, M7MCQ
www.m7mcq.com
Good afternoon Tom and very nice to hear from you, yes at one point in time I was of the understanding that the more fusing the better. From my reading, if your power supply has the proper protection then when there is an issue the power supply protection works faster than the inline fuse. As for the video on Larry's blog no I did not watch it but I did read the post. I think I was meaning to go back to it but as with things with me, I forget. Now you have reminded me I will go back have a look.
73
Mike
VE9KK
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