On 10/12/2014 10:19 AM, HM Dickson wrote:
I have an old 500 Swan that has been sitting a while. Pulled it out and find it blowing fuses. I can probably get it back up with a cap job and resistors but have no idea about the tubes. Were working 10 years ago when it was parked.

My question though is how to use this old piece QRP. Can I disable the finals and somehow run off the driver? What circuits to set output impediance and filter? What changes in tuning up? What about in CW mode?

I know very few would consider using a boat anchor for QRP but I need watching anyway I love the feel of the knobs and the tube audio.

If you got any thoughts, let me know.

73 AE4YW Mitch


You could, but it would take a major redesign of your output circuit.
You would have to disconnect the output of the driver from the final and
install a new final circuit (the output impedance of the driver stage
will not be the same as that of the finals).

And even then it will most probably still blow fuses.

The Swan 500 was a nice rig when it was new. If it were mine, I'd fix
the problem(s) and put it back on the air. It may need recapping - but
it might also be something much simpler.

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