The cooling fan?   Check for dirt or dust unbalancing the blades first. 

Use your ohmmeter to check the Primary winding carefully.  

If the primary is open, it may just be an internal thermal fuse that is in need of replacement.  

This can be done by disassembling the can if the transformer has covers, then slitting into the fish paper carefully adjacent to the two leads to the primary until you locate the little bullet fuse inline with one of the leads.  NTE has replacement temp fuses graded by temperature at opening.  

A rewinder would also know about this and replece.


73

Outstanding methodology there, Martin. 

It is still possible for a filament bulb to be faulty as to filament life even if the Current draw is correct for the bulb. 

It could simply be a case of the filaments being bad as to tungsten content or some other metallurgy anomaly, or even a case of the vacuum (which is often really an inert gas in filament lamps) to have allowed a leak and atmospheric gases such as oxygen are contributing to the shortened filament life. 

Use of the resistor in the rig and time should proof it either way. 


73

We have to consider that there was once a time when Noise Blankers were all about the famous "Russian Woodpecker" - and many hams judged the effectiveness of the NB as to how well it worked on the woodpecker. 

The rigs so far cited as having the "excellent" NB circuits are from that era, no? 

That pushed the rig designers to follow suit in order to gain sales advantage. 

Today, with the woodpecker not being what it once was, perhaps there is no perceived gain for the mfrs to go to the extra expense.


73

Might be that the amount of resistance of a bad solder joint affects things differently on different bands. 

The old D'Arsonval meter movements wth ballistic needles were not mean to be accurate on readings below somewhere around the top 2/3rds of full travel, so I'd be inclined to go with the reading on the DMM, regardless of purchase price. 


Presumably the current measurement was done *before* installation of the new resistor.


73

Bad connections/solder joints on the antenna might be the culprit...

I like the two foot long straight key...

All you need is a 1 ohm, wirewound resistor with suitable power handling capability.

1% tolerance resistor is good, but not mandatory here, a 5% tolerance would likely be good enough for determining the situation with the pilot lamp. 

Insert the resistor in series with the load you wish to measure. 

Measure the Voltage Drop across the resistor. 

Since the resistor is 1 ohm, the Voltage Drop will read out exactly the same as the Current value. 

Ohm's law. 

And, in this case, works the same for AC or DC Current Measurement. 


73

When's the last time you actually encountered a diode or transistor that was damaged by heat from soldering? 

73

When encountering repairs of this type, I first like to just sit there and STUDY the situation, making visual inspections, using magnifier if needed, and coming up with the best course of action in order to effect a good repair. 

*Sometimes it is necessary to lift a PCB off of its mountings in order to get to the other side, rather than tackling removal of things such as a bandswitch as cited here. 

*Sometimes necessary to *disconnect* wires in order to get to the place.  This should be done and documented, in the old days that meant taking notes with pencil and paper, making drawings, today I use the digital camera (or cellphone cam, same thing) to document wire placements, colors, etc. plus hardware assembly as it originally appeared as well as at various steps during the disassembly, such that there will be a guide to follow when reassembling. 

*Above all, I TAKE MY TIME on a project such as this one, often setting it aside until I feel reasonably certain that I will have both the time and the energies to devote to slowly and carefully working on the thing.  Use of that camera allows for putting the project to the side if necessary to relieve strained mental and physical facilities, picking it back up again at a later time when revived and able. 

If all else fails, and since these are xtals, I *might* resort to the old "top of the board" replacement techniques, ugly, perhaps, but functional.  Consider that most xtals of that vintage are made of cans that are soldered to the base.  Desoldering the can reveals the inner crystal plus its leads.  Careful disassembly from the top side until there is nothing left but the two leads sticking up through the board yields to places to solder in the new xtal.  A dab of non-acidic RTV or a glob of hot glue to physically "mount" the new crystal case to the board and you have a fast bug ugly way to effect the repair.


73

If it TRANSMITS anywhere outside of any Ham band, it has been modded. 

Just turn the Big Knob to a band edge, then turn past it and, with the rig attached to a Dummy Load and not an antenna so you don't break the regs, see if it will transmit there. 


73

It would then be interesting to have both the WT8005 and the newer WT8115U opened p side-by-side on the bench and perform a visual exam around the controller unit, looking for a possible pin that is not tied low (probably low, but might be hi) in one but not the other. 

That would mean that there is but one internal software going on, with differing feature sets selected by the state of different digital inputs on the chip, a common practice.  Much the same as the many radio "mods" for changing transmit/receive freq lockouts. 


73

Taking the time to insert AC mA meter in series with a single bulb should shed light on the light.


73

The OP never really stated what mode of transmission was being used for this "test" - if the mode was SSB, and not CW or FM, then the 60W figure coupled with a non peak-reading wattmeter would actually be about right. 

The past few years there seems to be a plethora of operators who do not seem to understand the workings of SSB, that it contains little to no Carrier and that reading the output wattage requires modulating the mic and use of a peak-reading wattmeter to see the full 100W. 


73