[Amps] OEP caps

[Will Matney]

I would assume that the glass epoxy was a cheaper alternative somehow. 
Most electrical will use the cheapest insulation to get the job done 
within ratings. I don't know how may the had made up, but they would 
have had to eat all those bad ones.

Yes, Cardwell is still plugging along and sent me a catalog about a year 
ago. The only thing is, they're generally higher priced than OEP in my 
experience. Keep in mind that OEP uses ceramic insulators on the air 
variable capacitors like Cardwell does. OEP also has a good "wiper" and 
bearings on the capacitors. The rotary inductor was the only thing I 
ever heard them having problems with. I'd say the reason was, they were 
new to making them. The only reason I ever had to replace an OEP air 
variable was due to arcing across the plates on load capacitors.

I think James Millen is still in business too. It was for sell and was 
even offered to me at one time. If someone had the cash, that would be a 
decent company to revive.

Will Matney


I wonder why OEP chose glass epoxy for the coil form, when there are 
easier to turn materials such as UDEL polysulfone that are extremely 
RF tolerant and heat tolerant. After all, they did use ULTEM which is 
another miracle polymer of recent vintage. Besides having lousy loss 
tangent at 1 MHz and up, Nylon also absorbs moisture, as does Delrin. 
Thanks for the tip about OEP products though. Does anyone know if 
Cardwell is still making capacitors and large coils too?

73
John
K5PRO