In article , nike
wrote:

Hi to everybody,
I need schematic of an antenna switch witout control cable, for selection I
must use coaxial cable.
It will be placed on the mast. I found something interesting on ham
newspapers but . . I lost it. via internet I try but if you use some search
tool (ie. google) you are sure to find all but not what you are looking
for.
Thanks in advance.
Nike



What K7ITM suggests is using DC blocks to put a DC control voltage on
the coax, and take it off again at the mast end. You can build your
own with a choke and a capacitor (both components well chosen), or you
can buy them already made. Depending on the company, they're called DC
blocks, line isolators, or bias tees.

These building blocks have three connections; a RF-only connection, a
DC connection, and an RF-plus-DC connection.

Key parameters include DC current carrying capability (which is also
affected by the coaxial cable you use), and SWR/insertion loss on the
RF side.

For low frequencies, SGC (http://www.sgcworld.com) sells DC Coaxial
Line Isolators (SGC catalog 54-70) good from 1.5 MHz to around 250 MHz,
handling up tp 1.5 amps at 25 volts.

At higher frequencies, Minicircuits makes Bias tees good from 1 MHz up
to the GHz range. You can often find these on eBay.

You can also find RF switches (relay and diode) on eBay.

--
Namaste--