// Home / Amateur Radio / Portable Antenna Mode V/S

Portable Antenna Mode V/S

A portable mode V/S antenna setup was constructed in order to work the AO-51 satellite in mode V/S, uplink on 145.880 MHz, downlink 2401.200 MHz. Both uplink and downlink in FM, so the Doppler correction on 2.4 GHz is really a challange around the TCA (time of closest approach.).

The 145 MHz part of the famous Arrow was used, with a custom made mounting for the S-band downconverter from Kuhne Electronic GmbH. A bias-T was used to power the downconverter. The patch was soldered for RHCP (the original instructions were for LHCP). The semi-water-proof was made of an empty salad box (the cucumber version works fine :-)).

The set up was succesfully used on AO-51 mode V/S. Several contacts were made with two FT817NDs, and a Heil headset. All powered from a single 2.2 Ah battery.

Thanks to John G7HIA for providing the patch antenna, David G0MRF for providing the 2.4 GHz source for testing, and AMSAT-UK in general for selling these items (and doing all other good things).


Here are some pictures from the antenna setup.

Portable antenna mode V/S setup PA1IVO

The complete antenna, the 70 cm part of the Arrow is removed, the 3 elements 2 m part is unmodified.

Portable antenna mode V/S setup PA1IVO

The 2.4 GHz parts are mounted on the Arrow boom through the existing holes of the 70 cm elements.

Portable antenna mode V/S setup PA1IVO

The 2.4 GHz patch, the downconverter (MKU LNC 24 OSCAR 2 TM) and the bias-T (KU BT 271 N), both from Kuhne Electronic GmbH.

Portable antenna mode V/S setup PA1IVO

A creative way of positioning the patch antenna by using a 90 degree N angle connector. The standard Arrow duplexer is not used and therefore removed from the antenna.

Portable antenna mode V/S setup PA1IVO

The patch antenna with the semi-water-proof box removed.

Portable antenna mode V/S setup PA1IVO

Again some creative mounting constructions, but it all works.

A YouTube Video

A YouTube video was made by EB4FBZ showing his 2.4 GHz receiving capabilities, but also showing my downlink signals (PA1IVO/P at 0:25 and 0:46) in Spain at the same time.

Parts for Sale at AMSAT-UK

The G7HIA 2.4 GHz Patch Antenna and the G0MRF 2.4 GHz Signal Source Kit are available through the AMSAT-UK online shop.

2011 by Ivo Klinkert, PA1IVO - Contact