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23cms gear

Hello Everyone

I’m interested in getting on to 23cms, I am currently considering the Alinco Tri-Band Handheld to act as the radio, however I’m unsure of what antennas to use. Has anybody got any recommendations for either commercially available gear or Homebrew?

Matt 2E0XTL

In reply to 2E0XTL:

Hi Matt, I’m homebrewing a transverter at the moment, hope to catch you on 23cm sometime S2S! It looks as though 23cm interest is growing - in these parts Robert GM4GUF has been operating 23cm from Tinto GM/SS-064 recently and is experimenting with antennas.

73
John GM8OTI

In reply to 2E0XTL:
Hi Matt
It depends on what you want to do really if its all SOTA, a handheld FM would get you some contacts but is limited longer term. It might be a good idea before you do anything to speak to someone near you who is into microwaves now, this could help. Also you will get an idea of activity in your area and maybe some help and advice. The “UK microwave group” is a source of information at £6 per year subscription if you get really into it!

I was lucky and picked up a DB6NT transverter secondhand which allows me to use all mode from my 817 but these are pricey new(about 1W output) I operate contests as well from hilltops for fun and there is a core of good operators on there on ssb/cw.

On antennas I have no experience of verticals, I use horizontal beams which are easy to use on the hill because of the tiny elements, they have much higher gain for a given boom length but are very much more directional! You can make a short quite high gain yagi, there are lots of designs about on the web. For example (but loads of others:
http://vitsch.net/ham/homebrew/23cm_beam/

Hope you manage to get on there, its abit more specialist with fewer ops up there but an interesting challenge if you want to look beyond FM.
Hope some of this babble helps.
73
Robert
GM4GUF

In reply to GM4GUF:
Many thanks for the suggestions, I have seen commercial 11 element beams from Sandpiper so may look at one of those as its only 1 metre long! Plus with that vertical FM would work well I believe!!

In reply to 2E0XTL:

OK hope to hear you, good luck with the sandpiper, I will be posting my activity for some 23cm SOTA contacts this year.

In reply to 2E0XTL:

I did use the 11 ele sandpiper beam fed with a short length of aircell 7. Works fine with the Yeasu FT-911 hand held mono-band. The Diamond SRH-999 also produces good results. This is the only antenna I use now as I see no point in carrying lots of radio kit on the mountains apart from a single hand held.

In reply to 2E0XTL:

My 23cm station for SOTA is quite simple, an old Icom IC-X21 handy producing 1W FM and a double quad antenna. The whole thing packs away into its own box for storage/carriage.



I did have a MickeyMouse 23cms transverter but its weight at 2.2Kg and low output and the fact they’re all Mutt’n’Jeff made it not really viable for SOTA. There’s a world of difference between the DB6NT gear and old MM stuff and about 30 years of technology improvements.

I did think about buying a DB6NT kit but for the better of part of 19 years I’d always wanted a 23cms handy and when this one, mint with most of the accesssories (including the original plastic bags, tie-wraps and boxes) appeared for £50 I had to pounce. :slight_smile:

Andy
MM0FMF

In reply to 2E0XTL:

Hi Matt,

I use a triband Standard C710 which is spec’d at 280mW output on 23cms. I use a quadruple quad (scaled version of the GW0VMW 70cms antenna, but using solid wire elements - see http://mw0idx.co.uk/quadruplequad.html ) usually held aloft in one hand with the rig in the other. The only downside is having to stand up and face the weather, but contacts are generally quite quick affairs. Usually I find horizontal polarisation to be the norm despite convention, though it is easy to change that to suit.

73, Gerald

P.S. Eventually looking to purchase a DB6NT transverter - my homebrew one weighs 2kg and is a non-starter for lugging up a hill, given what I carry already!

In reply to 2E0XTL:

I have an IC-12E which I usually use just on the rubber duck from the hills. Sometimes it helps to turn the rig on its side as most people are on horizontal beams. I monitor 1297.5 at home on a Kenwood FM only rig and my antenna is a huge vertical colinear. I do sometimes take a 19 element beam mounted on a photographic tripod up a local high spot when I am chasing an interesting 23cms contact.

Try http://www.merseyworld.com/wadarc/Technical_Topics/long-yagi-construction.pdf
by Chris M1EEV if you want to home brew an antenna. His design is based on one by DL6WU. I think that maybe the design could be adapted to use a plastic conduit boom like the SOTA pole to be more portable, it is on my to do list.

Steve GW7AAV

In reply to GW7AAV:

Many thanks for all recommendations!! I will investigate further and try and help the more obscure bands get some more air time!!

In reply to 2E0XTL:

Hello everyone

I have managed to get my hands on a 23cm transceiver, the radio will do FM, equally i have an 11 ele beam. I was wondering if anybody new if the polarisation on 23cm FM is vertical or do the majority of stations run SSB horizontal and as a result also run FM horizontal?

Matt 2E0XTL

In reply to 2E0XTL:
Hi Matt,

Nearly all ‘base station’ operators run ssb, horizontal polarisation, but most can do fm (still horizontal). I just orientate the handheld to give horizontal polarisation if needed. I also usually take a small beam, some other summit operators use a homebrew bi-quad. I wonder which rig you have ‘acquired’.

Regards,

Mike G4BLH

In reply to 2E0XTL:

Hi Matt,

The convention is vertical polarisation, but I usually end up with my antenna horizontally polarised as many people have beams since they can run SSB as well. I’d say be prepared to be able to swap over polarisation if you can and don’t forget to ask which polarisation to use if you are arranging a trial when working someone on a lower band.

Hopefully manage an S2S one day with you.

73, Gerald

In reply to 2E0XTL:

Are you going out with your 23cms gear on ISW? I’m going up Cairnsmore of Fleet on the Saturday and that has LOS view to many LD,NP,SS summits. Also LOS to Snowdown and a few of GW hills, LOS to most of the GD hills and LOS to a good handful of GI summits too.

I’ll be QRV on 23cms FM amongst a few other bands and would appreciate some S2S 23cms skeds.

Andy
MM0FMF

In reply to MM0FMF:

Hi all

Many thanks for the advice, Im thinking that my 11 ele will be the way forward and I will mount it on a camera tripod.

This will mean that rotating will be a breeze but i can then also change the orientation of the tripod panning head to suit if the beam is vertical or horizontal.

The rig is the Alinco tribander, im still awaiting delivery but will hopefully be QRV fairly soon! At home i run the IC910 so will have to try some experiments from my Local Hill WB-004 (Titterstone Clee)!

For international summits weekend i think it will be a struggle to get all the gear together! However i will be on all the bands from 70Mhz to 430Mhz

Matt

In reply to 2E0XTL:

all the bands from 70Mhz to 430Mhz

just 3 then :wink:

If you have the Alinco in time then stick it in your pocket. It can be backup for 2 and 70 and you may well work a few people on the rubber duck on 23cms anyway.

(Planning to be qrv 60m/30m/2m/70cm/23cm with 80m/40m on request)

Andy
MM0FMF

In reply to MM0FMF:

(Planning to be qrv 60m/30m/2m/70cm/23cm with 80m/40m on request)

My plans currently a bit uncertain (non radio stuff) but might get up Cairnharrow or Criffel (since you’ve bagged Cairnsmore of Fleet!) with the 23cm transverter if it’s reliably working by then. Might even have 1W output! Probably won’t have the dish done though.

73
John GM8OTI

In reply to 2E0XTL:

… will have to try some experiments from my Local Hill WB-004 (Titterstone Clee)!

Hi Matt,

I am fairly certain that the radar up there is L band and that’s 23cms territory. I could hear the rasp on 2m SSB when I activated the summit and I know the guys that used to operate 10GHz from there many years back had some issues even on that frequency. Might be worthwhile looking elsewhere - maybe The Long Mynd for ease of access or one of the other WB’s.

All the best,

Gerald

In reply to G4OIG:

A long time back I found some info on the NATS radar powers and Clee Hill runs 5 L-band frequencies simultaneaously with the ERP on each frequency being either 8GW or 16GW (can’t find info right now). That gives a combined ERP of either 40GW or 80GW and I expect that may indeed cause a minor amount of de-sense to 23cms users at the site!

EDIT: 8.1GW per channel and 3 channels. Threshold extension is used by chirping the tx pulse over 2.5MHz to achieve an 18dB improvement in the noise floor. So in fact its definitely QRP at only 24.3GW ERP.

Andy
MM0FMF

In reply to MM0FMF:

Hi Andy

It is my daughters birthday that weekend but I hope to be on at some point, not sure when but would be good to catch you on 23cm and others. Will have to be a last minute decision for the SOTA weekend and see what bands I can carry. Will watch alerts/postings.
73
Robert
GM4GUF