Batboard

The title says it all. What are the practical differences in these types of cables for permanent installations and/or test leads?

Filter equipment manufacturers seem to stick with RG142. Hams seem to think that RG400 is bigger and better. RG223 is not even on anybody's radar.

The difference I see is mainly the center conductor.

RG142 is silver over copper over steel. Stronger? More flex cycles?
RG223 seems to be silver over copper. Cheaper? The outer jacket is black and seems more flexible.
RG400 has a silver plated stranded center. More flexible I am sure. Better/worse than 142?

Thanks for any ideas or experience.

The 142 I work with is double shielded - braid over braid. That's all I use indoors for short lengths (up to 25ft) for rcvrs. Beyond that I use 1/4in superflex. I use 142 for xmit jumpers up to 2ft like to the duplexer or combiner input, or within the combiner between sections to the output. Any longer than that, I use 1/2in superflex.

For transmit jumpers you can also use RG393. It's the size of RG8, but made with Teflon like RG142 and RG400.
For test leads, RG400 will be slightly more flexible than RG142. Both have about the same loss, but still less than RG223 (polyethylene dielectric/PVC jacket). Double shielded cables are stiffer than RG58, so use straight connectors only. Make sure you have strain reliefs. Use the best quality connectors you can afford. Huber-Suhner makes some beautiful product. Also, double shielded cables CANNOT use normal RG58 crimp connectors, as the crimp ferrule has to accommodate the thicker shield.

If you care to examine the performance characteristics from an electrical standpoint for yourself, then please check out the following link:

http://www.timesmicrowave.com/calculator/

That should help you come to your own conclusions.

Obviously the lower the loss, the better the coax. Of course, there are caveats.

VE3HKB wrote:For transmit jumpers you can also use RG393. It's the size of RG8, but made with Teflon like RG142 and RG400.

Yeah... At ~$14.00 per foot. Not including connectors.

I never said it would be cheap. Start pricing quality assembly tools. Pin depth gauges.
Or precision, low RL, phase stable cables for sweep gear. $14/foot will look like a bargain.
You can pay any amount for cables and connectors - it all depends on what your needs and budget are.

You have to be careful when buying crimp connectors. Make sure they say "RG142/RG400" since these both have two braid shields and as mentioned the ferrule has to be thinner to slide over both braid layers. If the connector says it'll also do RG58, beware since that is the same diameter but only has one braid shield.

RG400 has a stranded center conductor and will flex much easier and more often. I use it for test cables and short runs that will never move. As mentioned, 393 is terribly expensive but it's what Motorola used on their Nucleus 900 MHz 300 watt transmitters. I use RG214 for everything else: double-shielded, silvered stranded center conductor, very easy to work with, but again you must make sure the crimp connectors have the correct (thinner) ferrule for the two braid layers.

Bob M.

I have always used RG142(unless for a high power application) and even TXRX uses 142 on the ham 1.2Ghz duplexer harness.