Kenwood TS-430 POwer Supply

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Joined: Tue Apr 22, 2014 8:31 pm

Kenwood TS-430 POwer Supply

Post by pcsf53 » Fri Jun 26, 2015 5:50 pm

I just found out that there are 2 internal fuses on the TS-430 pwr supply. One is soldered in and the other one is piggyback, held with clips. So both fuses are blown and the question is. Is there anyway to bypass or is this going to be a frustrating job to replace the fuses. Not much room to play with.

Thanks for any info/guidance.

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Joined: Sat Jul 01, 2006 8:32 pm

Re: Kenwood TS-430 POwer Supply

Post by N9LCD » Mon Jun 29, 2015 1:00 am


How long have you been licensed?

You ABSOLUTELY DO NOT bypass fuses. Neither do you replaces fuses with a different rating, 3 amps instead of 2, or a "Slo Blo" instead of a regular fuse. OEM fuses were chosen to protect the gear and you.

That was my safety rant. Now for the advice.

The fact that you've blown two fuses in the power supply indicates a short in either the power supply or in the rig. Download at least the schematic and, if possible, the service manual. With no load connected, check the resistances in the power supply versus the manufacturer's data. Allow plus or minus 10 percent. Check the power in and out cords for shorts.

If everything passes, THEN REPLACE THE FUSES! (Sorry!)

Then power up the supply with no load. If the fuses blow, you have a defective component that wasn't included in the test. Try again, checking each component.

If you power up the supply and the fuses don't blow, connect the rig. If the fuse(s) blow, the problem is in the rig before the power switch. If the fuses don't blow, power up the rig. If the fuse(s) blow, the problem is in the rig, probably past the power switch.

NOTE: Check if there any fuses in the rig and if they're the correct rating and type.

Believe me, this isn't easy. I once "smoked" a hollow state power supply with about eight different output voltages because I listened to an "Extra" class and used a "Slo Blo" fuse instead of a regular one!

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Re: Kenwood TS-430 POwer Supply

Post by k9yli » Fri Jul 03, 2015 12:40 am

The piggy back fuse with clips is just an easy way to fix a blown fuse thats soldered in.. Old TV trick.
There is really only one fuse. the soldered in fuse is now just a fuse holder.

But blown fuses are there to protect expensive parts.
alsol check the fuse for how its blown.
if its all balck inside with filament vaporised, then a serious high current short..
if the wire inside is just broken and sagging, the current was just slightly above the rating.
Sometimes called 'fuse fatigue'

If the same size fuse takes hours or days to fail, Its going to be a fun time finding the problem.
A fuse will blow if a spike hits it above its rating and blows instantly.

A fuse will also blow if current is barely above the rating but for a long time. It takes a while to heat up.

To trouble shoot fuse fatigue, if possible put a baby sitter amp meter in the circuit to monitor the current.
Check it often and under specific conditions. on recieve. on transmit only.. only on power up..
Try and determne the conditions that cause the failure.

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Re: Kenwood TS-430 POwer Supply

Post by KB3LMV » Thu Aug 13, 2015 6:34 pm

Hello Paul
It appears that someone had exceeded the duty cycle ratings of your PS-430.The ratings are 25% @20 A. 50% @ 15A 100% @ 10A.You might consider an Astron RS-35M 35amp Int. 25amp cont. or an MFJ-4035MV 35A int 30A cont.These are adjustable voltage and have both volt & amp meters.A very nice feature for detecting transmitter fold back because of antenna problems.
Hope this info is helpful.
73 4 Now

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