[amsat-bb] Antenna switching

[Rolf Krogstad]

Thanks to everyone who responded to my post.   Here is a summary of the
various option, plus description of my ultimate choice.

There were several good options:
Paul W2HRO suggested Sector Microwave SM7 switches.  Uses N-Type
connectors, will handle 1200 watts or more on 2 meters:  A Cadillac option
with $225 price tag.

Eduardo PY2RN sent a link to a PDF showing different options using manual
coax switches and/or multiple Diplexers.

Burt FG8OJ sent an eBay link to a $10 NAIS ARD62024 transfer switch - this
was the option I decided to pursue.

The ARD62024M01 has four SMA Female jacks, handles 120 watts at 3 GHz, has
.2 dB insertion loss at 1 GHz, and has gold plated contacts.  It is about
1.3 inches by 1.3 inches by 1.8 inches, or 32mm x 32mm x 39 mm (46mm
including SMA jacks).

The 24 at the end of the part number means it is a 24 volt relay.  This is
a latching switch, so momentary application of voltage to one wire switches
and latches it to Position 1, momentarily  applying voltage to another wire
switches and latches it to Position 2,

In Position 1: J1 <=> J2 and J3 <=> J4
In Position 2: J1 <=> J3 and J2 <=> J4.
So I put the 2 meter antenna on J1, 70 cm antenna on J4,
the receiver on J2 and transmitter on J3.

So in Position-1 the 2 meter antenna is on the Receiver and 70 cm antenna
is on the Transmitter.
In Position-2, the 2 meter antenna is on the Transmitter and 70 cm antenna
is on the Receiver.

Add a pair of momentary-on push button switches: one energizes the latching
relays into Position 1 (u/V), the other energizes the latching relays into
Position 2 (V/u).

I purchased 3 foot cables SMA Male on one end of all 4 cables, with the
other end of one a PL259 for my Yaesu FT-897 (used for xmit), two with
SO-239s for the 70 cm and 2 meter antennas, one with SMA-Male for the
Funcube Dongle Pro Plus receiver.

It works great - I love the latching relay concept.  That way a failure of
the power supply won't cause the antenna to flip from U/V to V/U, or vice
versa.

Total cost was about $85, $17 for each of the four cables and $10 for the
coaxial switch plus shipping.

Here is a link to the data sheet:
http://www.relaymall.co.kr/pdf/mech_eng_rd.pdf

Thanks again to all for the great ideas!

73
Rolf   NR0T
Grid EN34
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On Sat, Apr 14, 2018 at 4:17 PM, Rolf Krogstad <rolf.krogstad at gmail.com>
wrote:

> In the shack I am finally starting to use my Funcube Dongle Pro Plus with
> SDR-Console 3 and really am liking the combo, especially for the linear
> birds.
>
> The one downside is having to manually unscrew coax connectors to swap the
> antennas from receiver to transmitter and vice versa when going from V/U to
> U/V and U/V to V/U.
>
> I don't want to use multiple antenna switches because if I or a guest op
> doesn't set them properly I could blow the front end of the receiver.
>
> Does anyone have an idiot-proof solution for throwing one switch and
> having the two antennas swapped between rcvr and xmtr?
>
> Tnx es 73
> Rolf  NR0T
> EN34it
>
>
>