[HomeBrew] Re: Audio connector freq limitations? (Helmut Usbeck)

[chin-leong_lim@agilent.com]

I concur with Helm. 

The suitability of RCA connectors for routing RF signal is demonstrated in the home TV set, which must operate from 40 to 800+ MHz. They are used as interconnects between the chassis mounted aerial socket to the tuner module, and also between the tuner and the IF modules. 

There are many variantions of the RCA male connector; some are more suited for high frequency operation than others. The connector variant which allows direct soldering to the coax cable's shield (e.g. the ones found in the TV set) are probably just as good as regular RF connectors up to VHF. If used above 2m or so, I will be more concerned over the VSWR than the attenuation.

I am somewhat less optimistic over the performance of the RCA male connector with a plastic end-cap, e.g. the type commonly used in home-made audio interconnects. In the absence of any quantifiable data, I will consider it safe for use up to 6m. 

- ChinLeong, 9W2LC.

-----Original Message-----

Date: Sat, 4 Jan 2003 17:03:26 -0500 (Eastern Standard Time)
From: Helmut Usbeck <vze2gmp4@verizon.net>

  Never hear of that one.  Used Phone jacks and plugs for years.
Never had any problems with them.
One must remember that RCA connects were designed for one thing, cheap,
cheap, cheap.  Many of the older rigs used them for VFO input, but they
did need periodic crimping and cleaning for a good connection.  The Eico
720 transmitter springs to mind since I have one.  Replaced the RCA jack
with a BNC connector.  Much better.  Of course one could spend big bucks
on the RCA jacks that the audio guys use that are made out of machined
billet and gold plated.  But it's still a lousy connector anyway you look
at it.

Interested in why the acquaintance thinks that phone plugs and jacks
restrict the audio range.  He probably seeks out oxygen free copper and
paints the edges of his CD's with green magic marker.  Anytime someone
runs an off the wall statement about electronics across me I ask them to
qualify it.  They usually can't.

-Helm.  WB2ADT