[TowerTalk] ? AMERITRON REMOTE COAX SWITCH

[Tom Rauch]

> The current MFJ catalog's write-up on the RCS-8V is a
little
> confusing.  The first paragraph says you can control it
with standard
> telephone wire, which is 4-conductor, while later on in
the ad it says that
> it needs a 6-conductor cable.

The RCS-8V uses an open frame double make double break relay
and is good to just over 200MHz with negligible loss and
good isolation as measured on calibrated lab equipment. It
totally falls apart at 300MHz or so. The relays have
generally not been a problem as long as they are
occasionally transmitted through. (The RatPak uses the same
relay) The RCS-8 has an excellent RF layout, so RF
performance is exceptional for a medium size open frame
relay. The control current is 100mA so the line can be
small, like a four pair telco line. It has high lightning
protection for things downstream, like your radio.

The RCS10 uses a ladder arrangement of sealed relays. It
offers very minimal lightning protection, works at 2 meters,
but has poor port-to-port isolation. It uses a three wire
(+gnd) control.

I've just been doing sweep, loss, isolation, and voltage
breakdown tests on relay systems, so all of this is right in
line with what I have been measuring in the past few days.
When I get done I'll post the printouts.

I wouldn't buy anything just yet if you are looking for a
quality system without a look at the DX Engineering booth at
Dayton.

73 Tom