23cm or 13cm

Im looking at having my first dabble in high UHF/ microwaves and including it on my SOTA activations.
Ive decided on a transverter from SG-Lab but stuck on which band to work, id quite like to do both but the budget doesnt stretch that far.
so which is the most active 23 or 13cm?


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Hi Steve,

I’m sure you will get different opinions, and there are more experienced activators than me.

But, here are my thoughts - I have used 23cm on several activations, and 13cm on a couple, SG Labs transverters each time.

There is probably more activity on 23cm generally, and you might well achieve a QSO or two just by calling CQ (unless you are at the fringes of UK, or surrounded by higher ground). Use FM as well as SSB / CW.

13cm is more of a niche, but you will be popular with the enthusiasts on that band. It would be wise to arrange a sched or two in advance, as you are unlikely to get contacts by calling CQ outside of UKAC / contests.

Good luck and have fun!


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I would go for 13 before 23. Part of the 13cms band is shared with wifi… we’ll always have access to that. 23cms is under serious threat from GNS demands.

QRV for SOTA on 80m/40m/30m/20m/17m/15m/12m/10m/6m/2m/70cms/23cms/13cms

3cms and 1.2mm on the way.

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Thanks for the quick replies chaps.

i was leaning towards 23cm but as @MM0FMF says it is under serious threat. a quick google search produced this article from AmSat Link which is very worrying indeed.

13cm could be the option but as @G4AZS put it, its a niche band but another operator on it could invite more activity

im not in any particular rush so for now i think i will hold back, wait for a few more inputs on this thread and do a little more research on the 2 bands themselves


Actually Steve considering the state of the world and what might happen, just go and buy the 23, 13 and 9cms boxes and use them while you can. :slight_smile: IIRC your QTH is NE England and there are plenty of uwavers up there to chase you. They don’t check SOTAwatch as a norm so you need to make noise elsewhere (newsgroups etc. ) so they know you will be going out portable.

Like Andy I operate both bands, there are pros and cons for each.

23cm is easier to get random Point 2 Point (Pt2Pt) QSOs because there is more kit around. There were 23cm handies and the ICOM 9700 plus other rigs have 23cm capability. You need to be able to switch between Vertical and Horizontal polarization with ease on the summit, the 23cm contest / fixed stations will be horizontal and the handies are vertical.

13cm has the advantage the SG-LABs transverter will also work on the uplink of the QO-100 satellite. In general, most of the summits activity for 13cm is in central Scotland. However, we do have skeds in G/LD via the QO-100 Satellite and Pt2Pt. The Pt2Pt frequency is 25kHz (2399.975MHz) below the Sat band so we don’t have to reconfigure the SG-Labs transverter.

Both bands are represented in the UK Activity Contests (UKAC) so it is possible to activate a summit on either of these bands once a month. However, I see your QTH is some distance to summits.

FYI, I have 89 uniques on 23cm and 28 uniques on 13cm.

Which order to get them in is the question. If you have an interest in the QO-100 satellite then 13cm is the answer because it will get more use from the home QTH as well as some summits. If the main interest is SOTA activations in the Midlands and Northern England then 23cm is a good starter. In both cases you need to build some alerting to get contacts on either band other than UKAC nights.

The other thing to consider how do you intend to drive the transverter, if it is FM from a handi then that cuts QO-100 out so 23cm is more likely to produce results. For UKAC and QO-100 you will need SSB e.g. Yaesu FT-818 etc so 13cm comes back into the consideration.

Ultimately you have to decide.

73 de

Andrew G4VFL

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I drive my 23cm SG-LABS transverter with the 2M board built into my KX3. This set up gives me utmost flexability - SSB, FM, CW. The SG-LABS 25W amp is currently in transit to my QTH - I ordered this to take advantage of summits to try for DX thru the CA Central Valley from NorCal to SoCal; and to try to work from SoCal to AZ. There is a significant number of SOTA activators in AZ but few in CA. Most SOTA activators use the Alinco DJ-G7 HTs (that is how I started) but the microwave enthusiasts use the IC-9700 and others and generally focus on SSB. Antennas range from the ducky on the HT to the WA5VBJ PC board 3 element yagi, to the cheapo 10 element yagi, to the Comet 16 element and to the M2 22 element - Choices depend on how much you want to carry and what you want to accomplish. Here in CA there are a few drive up/short hike summits where larger antennas are easy; other summits smaller is better. I agree with those who suggest contacting the microwave aficionados - my best 23cm chasers and my best microwave DX come from those groups - I alert them separately/individually by email/text when and where I’ll be on a summit. As to 13cm or 23cm - around here 23cm makes the most sense - the microwave enthusiasts jump to 3cm (and I just can’t figure out how to get 3cm to summits!) Good luck with 23cm - it adds a special flavour to SOTA operations.

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Another thought - There are a few nearby lower summits that overlook the Pacific ocean - one day I hope to try the tropoducting path to Hawaii - it has already been accomplished by the microwave enthusiasts and it sounds exciting for SOTA. Each morning I check Hepburn Tropospheric Ducting Forecast for VHF & UHF Radio & TV and I need to find a SOTA activator for the other end! Like I said in my earlier post - microwave adds great possibilities to SOTA!

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Thanks for the very indepth reply Andrew thats helped clear things up no end.

I think i will go for the 23cm box to start with just for the activity level, then at some point try out the 13cm and QO-100, just been reading OZ1BXM’s article LINK on his setup for working QO-100, interesting stuff and not as expensive as i thought to get the kit to work it.

not really aware of anyone in my Amateur circle that uses the upper-UHF/Microwave but getting out for the UKACs as you suggest would give me more contacts and get to know whos around on the band, then let them know when my activations are, aswell as alerting and spotting on SOTAwatch ofcourse.

thanks everyone for your input, ive learnt alot from this thread


Hi Steve, glad you posted this, and I hope you will take my input. I have been on 23cms for a while, but never pushed for contacts until recently. you will always have chasers during the UKAC’s especially in the Northwest (inc GW/NW , G/SP, G/LD. I have a SG Labs pre-amp/amp connected to my 9700. I have ordered a SG-labs transverter to go portable with using my IC-7000.There a growing group locally here that are asking to promote SOTA 23cm activity including me. Hope to catch you out there with possible S2S’s. Especially when I get another preamp and yagi for portable use

73 Tony

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Hi Tony, thanks for your reply, your input is most welcome. Thats great that there is a good following of 23cm in the NW because thats around where most of my SOTA activations are going to be based, in G/SP G/NP and G/LD. Look forward to getting on it and seeing what the fuss is about and probably catch you on it at somepoint, i thought i recognised the calllsign and just checked my log i worked you on 2m-fm from G/NP-009 on Sunday before the battery died :roll_eyes:


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