OK, I give up. Who supplies the highly recommended FairRite Products 2873000202 core that is used in all the matching transformers. I would like to try a few, but can't find them in the Mouser catalo
CWS Bytemark has them for $0.60 each. Their P/N is B-202-73 and S&H is $5.00 for priority mail, although it seems to take them several days delay to be ship. http://www.cwsbytemark.com/prices/wideban
I recently bought a quantity of the equivalent part (BN-73-202) from Amidon along with some small diameter Teflon tubing (recommended to reduce capacitance between windings). They're in Costa Mesa, C
A little company called Ocean State Electronics carries many popular styles of ferrites and iron powder cores in various shapes and sizes. They are under Toroids in the index. http://www.oselectroni
Thanks to Don, Ford, Bill, Augie and Charlie, I now have several sources. I've become used to using Mouser and Digikey and had just forgot about the other sources. Thanks fellows. 73, -- Ken K4XL k4x
"OK, I give up. Who supplies the highly recommended FairRite Products 2873000202 core that is used in all the matching transformers. I would like to try a few, but can't find them in the Mouser catal
Btw, type 73 material is conductive, so you need to sleeve the core or use wire with a thicker insulation than enamal. If you are happy to use twice the number of turns, then consider using 284300020
secondary within a teflon but clearly touches W2PM You should avoid scratching through the enamel, especially if the core contacts another conductor. Normally enamel is not a problem, but at times i
layer of enamel is used it can be scratched through. Actually you don't want to scratch the wire with ANY core. The reason is pretty obvious, that bare spot might touch another bare spot in a winding
The only way I have managed to keep matching transformers for my 900 foot beverage is to mount the transformer inside a defunct tube base and mount a corresponding socket in a weather-proof box (I u
But it does seem that reasonably careful winding with decent enameled wire should not be a problem. But I have another question for you, Tom. #73 is pretty lossy, whereas #43 is a lot less so. It isn
A short shows as a very noticeable impedance error. What you might do is test the transformer while wiggling the core and winding gently, and if it is all OK give it a shot of Krylon. I use double i
lossy, what the concerned. Doesn't matter much. Loss is a fraction of a dB. On transmitting, a fraction of dB makes a lot of heat at 1500w!!!! _______________________________________________ Topband
FWIW....I like the "wire wrap wire" one can buy at Radio Shack. It's #30 with a tough plastic insulation that comes in various colors. I use Sears Craftsman #73574 wire stripper to remove it. 73, Ch
Minicircuits coats their cores with "Parylene". The cores are conductive like FairRite73 and are in fact probably similar material. A long time ago, a batch of uncoated cores managed to find their wa
"I have been using no.27 enamel wire with only the secondary within a teflon tube in the core. The primary is wound around the telfon but clearly touches the bare core -- are you saying this is not g
With the "Battle Creek Special" verticals, we need to use a 2:1 UNUN for the 160 m Inv L section. We've been using 61 type material and glass tape the cores to prevent the sort of problems described
My experience is based on the use of these cores in receiving antenna applications ( low noise transformer feedback amplifiers ), over the past 9 years I have wound thousands of transformers using tw
Hi Rick, That's interesting that Mini-Circuits used Parlyene. It's a very expensive material to use although a great solution to the problem. We have a Parlyene coating system at work and due to the