183 Build Questions

[donvan]

I have most of the parts for my #183 build. Just a few things I'd like to ask before I get started with the build.

1) I've done a lot of searching regarding the best coax for a Dumble and I don't really see a consensus. It seems like capacitance around 30pF is important. It also looks like Dumble's coax changed over the years so I suspect best coax depends on what you are building. Anyway, what is the consensus for a 183? I see where one person said that you really need RG400 for a #183 but I didn't really see a consensus on that. I do have some RG179 on hand but it is only 23pF/foot.

2) In the tone stack, there are 2 22Meg resistors. I was only able to find 1/4 watt resistors. Will those work or do I need 1 watt resistors there?

3) The impedance switch - digikey 690-D4G0303N - is a part that I think many have used but it is really long and would stick way out the back. What have others done? Cut it shorter?

[mojotom]

1/4w is fine for the PAB, I think he used some 1/4W carbon comp on some build.

You can cut the axle of the impedance switch if needed.

Not a real consensus about coax. I would try to locate the white coax for 183 vs RG59 on older amps.
Some use RG319, some RG400. I use RG187 as it was what I was able to find easily and buy per meter.
I can't help much on that point.

[norburybrook]

IMHO the runs are so short I doubt it makes any difference


M