Henry usage

[AardvarkM31]

Will the length of the wire used for the coils of a 1.5" diameter pvc pipe set for the AM Broadcast band,  give the same performance/requirements/selectivity  if this length is wrapped around a 3.5 in form?

[T3sl4co1l]

What dimensions would the resulting winding have?

L and Q will almost certainly be different.  Presumably you're working for a design that needs some nominal L, so other values (beyond of say 10% of nominal) will be bad, and lower Q would be bad.  Which ones apply, I have no way to guess.

Tim

[TimFox]

In my MRI days, working on relatively low field magnets with correspondingly low RF frequencies (5 to 10 MHz), I found that the dielectric loss in PVC coil forms had a bad effect on inductor Q.  Polystyrene, polyethylene, and polypropylene were much better (only polystyrene in that list is glueable), and acrylic (Lucite) was mediocre.

[Wallace Gasiewicz]

Here is a formula.

https://66pacific.com/calculators/coil-inductance-calculator.aspx

[Terry Bites]

I used scrap 180mm MDPE Gas Pipe for a LW receiver.
The bigger the diameter the fewer turns so less R and more Q and a higher self resonance frequency which is hopefully out of band.

[AardvarkM31]

Thanks Tim and I didn't think it would be that easy... Well I guess I will start with the Boys Beginner crystal radio book 

[AardvarkM31]

Yes, I am not that far along to worry about the materials. Kinda looking for a quick and Relatively easy project. Picked one a bit more complicated than I originally imagined.
Thanks

[AardvarkM31]

Thanks kind Sir, will give it a go!!

[AardvarkM31]

Helloo and thanks, I am now getting the idea that I don't know nearly enough. Wanted to start with grabbed info from TY videos and modify. Not such a good idea.