My answer will differ from some of these others.  

It really depends on the internal construction of the bipolar output device in question.  

Some are monolithic, but others are actually many smaller junctions internally wired in parallel inside.  

Should a junction become shorted, the tiny interconnect wiring will fuse, dropping that particular junction out of action.  

As junctions get cut off in this fashion, power output drops accordingly.  

This can happen, of course to more than one junction in the parallel string, resulting in the condition known as a 'soft' RF Output Transistor.  

However, these days you are more likely to encounter that situation with transistors designed to work at around the VHF level and higher.  

Voltmeter and Ammeter on the power, dummy load and wattmeter on the output, my preferred mode for this kind of testing is CW mode, this is the way to sort the problem properly.  See if you have the proper output and proper load draw before arriving at any conclusions.  


73

If John tried my step three, with dummy load at low power, it is rather doubtful that ferrites are going to help here. 

That reversed ground lug problem was a Heathkit fiasco that apparently went on for quite some time. 

The terminal strip included with the kit, typically the two-lug strip that connected the coax from IF output to the AF section, was built backwards from the one in their pictorial. 

So if someone followed the way it looked in the pictorial, but did not notice that the Ground Lug was on the wrong side from the pictorial, the end result was a totally quieted receiver. 

Can't recall how many I troubleshooted for other hams where this was the only problem, but it included a LOT of HR-10 receivers for a year or two back in the middle 60s.  And, of course, a few other models as well. 

73

Or find something else that may be completely different from ham radio and do that for awhile. 

The gear and shack will be waiting when you get the juices back for it. 


73

I was thinking along those lines when I read the post yesterday, but having no experience with replacing the string on this antenna, I held my thoughts. 

Over the years I've found out the hard way a few times that it can be a problem to resist the concept of overkill when repairing or refurbishing things, both electrical and mechanical.  We tend to think towards what would be a PERMANENT solve to a problem that may not ever rear its ugly head again, at least not in our lifetime.  Often can be the case that such modifications, if not well thought out in advance, can actually end up being detrimental to the device, sometimes even ruining the device and that's not good either. 

However, we've come a long way baby since that antenna was designed and built, likely using organic compounds in the string and there are certainly "strings" available today that would still bring the particular qualities of the original string yet be able to last much longer, resist UV, stretching, roting or tearing better than the original. 

TIP:  I'd be heading to the local Fishing Tackle store, dial calipers in hand after measuring the average diameter of the original string, looking for a high pound test woven fabric "string"... 

73

Mho, Larry and Curly...

Very good advice from Dick here, the RF Gain Control is one of my most often used controls, backing off the receive sensitivity via the RF Gain Control once a signal is located can make a big difference in copying CW, headphones or not.  RF Gain can lower the apparent Signal-to-Noise Ratio and when the mode is CW, can make a very easy and enjoyable listen, almost like FM a lot of the time, and that can also translate to a longer time before the dreaded Ear Fatigue sets in. 


73

That must mean that most of the receive section is working.  

Investigate the switching between WWV and the other bands, could be a dirty switch, misaligned, broken contact, something like that.  

Might also be in the Bandswitch...


73

You've already lost any argument the moment you resort to the ad hominem attack, y'know...

It means that you've run out of salient ideas. 


73

Strange methods masquerading as thinking around here. 

First, make something up out of the blue, then proceed to get angry about it? 

Hearsay evidence is no evidence at all. 

Low information consumers. 


73

Now I'm being lectured on energy density. 

gotta luvit


73

When adding or replacing the 130VAC MOVs here, I use 3 to protect each line. 

One from Line to Neutral.

One from Neutral to Gnd

One from Line to Gnd

I place them inside plugstrips usually for shack and testbench use, and I have made it a habit to just blanket replace any found when picking up a used plugstrip on the cheap, garage sales, thrift shops, etc. - which is where I get them for pennies on the dollar. 

73

How Lithium battery technology got into Graphene capacitor shortcomings is a puzzlement. 

Meanwhile, the non-Graphene Supercap has all but replaced the use of Memory Cell batteries in everything from ham radios to video receivers. 

The designs of humans are always things that must consist of tradeoffs. 

Somehow we've managed to get by using the stuff despite the tradeoffs. 


73

"Turn the Big Knob!"   -- Riley Hollingsworth

The OP should do something in the way of ISOLATION of the reported problem or all answers are mere conjecture. 

**Substitute another set of headphones of any kind, even cheap earbuds, just to see if the problem persists.**

**Try the several CW modes available to you, such as Full Breakin, Semi QSK, and manual to see if the problem persists in all.**

**Try it with the rig connected only to a Dummy Load with short jumper.  Vary the power level from low to high to see if that affects the reported problem as well.**

**Try it into the antenna again at varying RF power levels, see if it only happens when sending full power but perhaps does not happen at say the 5 or 10 W level, indicating an "RF in the shack" situation.


73