Dead radio?

I was trying the FT8 digital mode for the first time on my new Flex 6500. The radio was in (full duty cycle) FT8 transmit at 100 watts into near perfect SWR when I heard a ‘pop’, after which, the radio would no longer power up.

I immediately assumed I had blown up the radio…

Yep, you could say I was a little ‘bent out of shape’. All I can say is, it’s a really terrible feeling. Mostly, I was angry at myself for having blown up the radio. Mega p1553d was more like it…

After regaining some composure, I noticed some of the other 12V gear, not in use at the time, was also off. So I pulled out the voltmeter, and sure enough (and much to my delight!) there was no DC on the power lead to the dead radio!

How Do You Spell Relief?

I immediately connected the radio directly to the power supply and started dancing when the radio powered up. RELIEF is not a strong enough word in this case.

As it turned out, I had blown a fuse in the MFJ power strip!

The culprit: 15A 32V fuse

Can’t blame MFJ for this one! This is what happens when you try to draw 25A through a 15A circuit. A rookie mistake.

Easy to replace….If I can find one!

A couple of local stores are showing them in stock. This is a 15A/32v fuse.

In an effort to take some of the load off the MFJ-1118 I will connect the two 6000 series radios directly to the power supply. The MFJ-1118 is not relied upon to protect the radios, and I now realize that having it inline with the radios is wholly unnecessary.

The most time consuming part of this problem was getting the power strip out of the rack! I had installed the MFJ power strip inside the rack behind the Flex 5000 and now realize it was a design flaw to have located it there.

After replacing the fuse, the MFJ-1118 will be mounted to the exterior side of the rack for easier access going forward.

OK, so by now, I’m sure you’ve figured out how I got myself into this situation!

In error, I had connected the Flex 6500 to a 15 amp circuit. While in full duty cycle transmit the radio requires 25 amps. Hence the pop!

I’ll replace the fuse, change my shorts, Hi Hi, and go on my way a little wiser.

UPDATE: Found the fuse at Home Depot, replaced the fuse and tie wrapped the MFJ-1118 to the side of the rack. Reconnected all the 12v gear, and everything is back together.

I should have mounted it here to begin with!

Back To The Front

Author: K6HR

Licensed since 1994. Active on HF / VHF / UHF / Satellite.

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