How do you get on 23 cm 1296.2 MHz USB for SOTA activations without forking out loads of dough for an ICOM IC-910 or IC-9100? Answer a lightweight all mode 2.5 watt 23 cm transverter from Hristiyan LZ5HP in Sofia Bulgaria. The current unit on offer is version 2.3.
The 23cm transverter’s default configuration is simplex with the local oscillator (LO) set to 1152 MHz. The unit has internal jumpers to change the LO frequency by +/- 2 MHz, this option permits simplex operation on 1294 MHz FM. A separate jumper configures the unit for simplex or repeater operation while a fourth jumper configures the repeater offset which in VK is 20 MHz. We don’t have a 23cm repeater in VK1 so the unit’s ‘Repeater’ and ‘offset’ settings aren’t required. I plan to operate the unit as an all mode simplex transmitter.
Under the cover the unit is complete with an adjustable Rx pre-amp between -5 dB and +10 dB gain.
Photos: © Copyright 2017 Andrew VK1AD
Supplied with the unit is a HB9VC 23 cm yagi antenna ready to go. You will need a short length of RG316 or equivalent coax fitted with male and female SMA connectors. The HB9CV antenna is fitted with a standard male SMA connector which mates with a standard female SMA connector. Do not use reverse polarity or reverse gender (RP-SMA) connectors.
SG-Lab 23 cm transverter power consumption is 80mA on receive and 800 mA on transmit. Jumper settings are on the right. Rx and Tx are adjusted separately by each of the two ‘white’ variable resistors in the centre of the board. I adjusted the transverter’s power input/output setting with the 817 power output set to 0.5 watts. This is a set and forget arrangement, however you must remember to always check the 817’s power output setting between one operation to another or when changing bands say from 2m to 40m and later returning to 2m where you may have changed the 817 power output to 5 watts. A point to remember when you are out in the field. 😉
Sunday 18 June 2017 – Out in the field operating on 23 cm from the summit of Mt Taylor VK1/AC-037 at 854 metres ASL. PCB antenna is mounted on a camera tripod.
Temporary improvised mounting arrangement for the WA5VJB 3el PCB Yagi antenna. Antenna is resting against a section of grey perspex mounted on a camera tripod. Antenna pigtail is a short length of RG174 soldered to the board, not ideal but will do for now. I will figure out a better mounting solution. 🙂
Testing the supplied HB9CV antenna, transverter power output is approximately 2 watts at 12 volts and 2.5 watts at 13.8 volts.
My next task is to construct a 12el 23 cm yagi, approximately 700 mm in length. I am well on the way with the reflector and 10 director elements cut to size. The PCB yagi antennas will prove useful for local VK1 peaks and distant VK1 summits in Namadgi National Park where carrying a Yagi antenna is problematic due to the density of the forest regrowth following the Canberra 2003 firestorm. I am keen to try out the PCB antennas from home as a SOTA 23 cm ‘chaser’.
Extract of VK1AD SOTA Activator Log: 17 – 18 June 2017 Mt Taylor VK1/AC-037 on 23 cm 1296.200 MHz
|21:58z||VK2NSS||144MHz||SSB||Steve s59 r59 0.5 watts|
|22:05z||VK1KW||144MHz||SSB||Rob s59 r59 0.5 watts|
|22:06z||VK1MT||144MHz||SSB||Matt s59 r59 0.5 watts|
|22:15z||VK1DA/2||1240MHz||SSB||%QRA%QF45ME% Andrew s58 r59 S2S VK2/ST-053 60km|
|22:16z||VK1KW||1240MHz||SSB||%QRA%QF44MT% Rob s59 r59 19 km|
|22:17z||VK1BG||1240MHz||SSB||%QRA%QF44MS% Ian s59 r59 15 km|
|22:19z||VK2TWR||1240MHz||SSB||%QRA%QF43PL% Rod s51 r41 Nimmitabel 130 km 2.5 watts|
|22:29z||VK1DA/2||1240MHz||SSB||%QRA%QF45ME% Andrew s58 r59 S2S VK2/ST-053 60 km|
|22:40z||VK1MA||1240MHz||SSB||%QRA%QF44MT% Matt s58 r59 19 km|
|23:08z||VK2DVM||144MHz||SSB||Dave s52 r52 in Sydney 260 km north-east at 5 watts|
|23:13z||VK1ATP||144MHz||SSB||Paul s59 r59 Canberra at 5 watts|
|23:35z||VK2COW||144MHz||FM||Dimitrious S59 R59|
|23:57z||VK1MBE||144MHz||FM||Andrew S59 R59 Canberra|
If you are as keen as I was to get a leg in on 23 cm SOTA activations, then an all-mode 23 cm transverter might be a feasible option, it was for me. 🙂
Good luck with your 23cm SOTA activations!