[R-390] R-390A Antenna matching, 26Z5W, 3TF7, 0A2 replacements available? Recommendations?

[Perry Sandeen]

Yo Bubba Dudes!,
Sigmaperts are high quality beautiful looking parts.

 IMNSHO, they are a very poor value for the money spent. I admit that I take a value approach out of necessity and the low cost solutions I favor are far from aesthetically pleasing but work as well.
The Sigmaperts antenna matching balun is very nice but there are DIY circuits available on the web that can be made for less that $5. And the question arises: do you really need it?  Transmitters yes, receivers are usually very happy with the longest single wire one can provide.

Replacing 26Z5's with silicon diodes and a 300 - 500 ohm power resistor will cost less than $2.
3TF7's have been happily replaced by many members with a simple dropping resistors.  There are some slightly more exotic solutions going back to the days of the Hollow State News which featured a number of circuits in its publications that are free on the web.
If you want something a bit more sophisticated there is one on ebay for about $28 that's had good reviews.

An 0A2 SS replacement can be made of less than $2. If you go to the R390AFAQ site. I've posted a SS regulated PS circuit that uses one HV 3 terminal regulator IC, 3 1% MF resistors and 2 caps.  New from Mouser would be $5 at most.  The advantage of the IC regulator is that you can add far more (.01 mF) bypass capacitance at the point where the +150 goes to a tube pin. Also one doesn't need the high wattage dropping resistor that goes to the 0A2 input.
A 0A2's useful life and stable regulated voltage output is directly related to the current it is dropping. There is an article about it in the SP 600 anthology. With the 0A2 one is limited to about 5,000 pF max as any more causes it to behave as a relaxation oscillator.
Sigmaperts also sells plug in replacement filter caps for IIRC $85.  It is very pretty. A number of posts to the list have shown several far less expensive alternatives.
So you pays your money and make your choices.
Regards,
Perrier