Hans,
Isn’t there an issue with antenna system bandwidth on 2200m, I wonder if anything other than CW or digi modes with very low freq shift is feasible.
It may be worth having the option of extending a QMX+ down to 630m though.
There is a transverter available from minikits (AU) for 630m but only the keen go that far. and I don’t think we’ve seen any sota activity on that band (yet).
Intrigued to see what you come up with for those bands.
73 Andrew VK1DA/VK2DA
Not quite right… not a successful SOTA activation… I was on DM/BW-018 with my 630m transverter and heard Roman @DL3TU—who was at home—but he couldn’t hear me.
I will improve my antenna, and we will try again.
73 Armin
Hello Andrew
It’s a good point about antenna bandwidth on 2200m being potentially less than SSB bandwidth. I suppose this is yet another challenge associated with 2200m operation.
73 Hans G0UPL
I had several summit activations at noon on 630m in the last years. ODX was 90km.
V2,DL1CR/P,DM/NS-122,22/08/2025,10:15,VLF,CW,DK8OA/P,437kHz tx 145.450 rx crossband
V2,DL1CR/P,DM/NS-122,30/09/2025,12:20,VLF,CW,DF5QG
V2,DL1CR/P,DM/NS-163,26/08/2025,10:00,VLF,CW,DL6OBJ,Crossband
V2,DL1CR/P,DM/NS-121,31/08/2019,14:30,VLF,CW,DK1HW
V2,DL1CR/P,DM/NS-122,24/11/2022,11:02,VLF,CW,DL6OBJ,472.400kHz
V2,DL1CR/P,DM/NS-008,03/09/2019,10:40,VLF,CW,DK1HW,473khz
Here is a clip made on DM/NS-163 together with Uwe, DK8OA. You can hear my 630m signal retransmit on 2m by the chaser.
73 Chris
So Hans, does that mean it would ONLY ever do 2200 to 80m, or would it be switchable/swapable to revert it back to 160 - 6m?
Warren vk3byd
Antenna systems suitable for transmission on the 630m and 2200m amateur bands are usually significantly shorter than the wavelength, with radiation resistances in the range of just a few ohms on 630m and less on 2200m. Ground resistance, on the other hand, often falls in the 20–100 ohm range unless a total of 1 km or more of buried radials is used. Consequently, the bandwidth is surprisingly wide.
73, Chris
I have gathered the results regarding the 630m band in the Dropbox at spota.dl1cr.de and created a few clips covering the basics in german. I plan to transfer everything to WordPress over the next few days.
73 Chris
It would be a specific 2200m / 630m / 160m / 80m QMX+ that is built for these 4 bands only, not switchable or swapable back to 160-6m.
Reasons for this are that the output power transformer, RF choke, and receiver phase splitter all require significantly more turns for LF operation than they do at HF. It therefore isn’t practical or proposed that there be an easy way to switch back and forth between LF operation and HF operation. Also HF operation uses PIN diode switching.
To make an LF QMX+ would require some relay switched filters for 630 and 2200m. My suggestion is a daughterboard which mounts on the normal QMX+ board IN PLACE OF the existing LPF section, and holds the necessary filters for 630 and 2200m operation.
I think this would be, as Armin DL6GCA commented, a rather unique transceiver.
As for the previous question by VK1DA about antenna bandwidth being wide enough:
Isn’t there an issue with antenna system bandwidth on 2200m, I wonder if anything other than CW or digi modes with very low freq shift is feasible.
I interpreted this as saying SSB is too wide for the antenna bandwidth; I have since learned that SSB is not permitted on 2200m anyway.
However the SSB capabilities of QMX+ would still potentially be very useful. Bear in mind it has the high performance “DiGi” mode where incoming modulated audio from the host PC has its audio frequency measured, then this is added to the notional “USB Dial Frequency” and the necessary RF is synthesized cleanly directly at the transmit frequency. This works only for FSK modes. For any Digital modes such as VARA or PSK31 involving phase shift modulation or multiple tones, the SSB mode in QMX+ is required to modulate these. So the SSB mode would still be useful in QMX+ on 2200m because for certain types of narrow digital modulation (involving multiple concurrent tones or phase shift keying) an SSB exciter is required.
Seems like an interesting project!
73 Hans G0UPL
I’d thought this was not allowed, as you say, but I can’t find any such restrictions in the Radio Spectrum Allocation or GURL (license conditions) for ZL. Where is this restricted? In individual country’s licenses, or some ITU international level document?
I’d thought this was not allowed, as you say, but I can’t find any such restrictions in the Radio Spectrum Allocation or GURL (license conditions) for ZL. Where is this restricted? In individual country’s licenses, or some ITU international level document?
Maybe you are right, ye, maybe SSB IS allowed on 2200m…
The 2200m Wikipedia page 2200-meter band - Wikipedia refers to the 2005-agreed ITU Region 1 band plan, it includes Telegraphy and Digital modes but not Phone. BUT - that’s only Region 1 and an ITU band plan is not the same thing as a legal regulation under a country’s own spectrum authority e.g. FCC in US.
I note that the ARRL page https://www.arrl.org/frequency-allocations does include Phone in the list of modes for 2200m. But this is also not equivalent to a binding license condition, just because it’s on the ARRL frequency allocations page.
Practically speaking the 2200m band allocation is only 2.1 kHz wide but that also doesn’t preclude an SSB QSO taking place: 2.1 kHz is sufficient for SSB.
73 Hans G0UPL
Our site, SPOTA-LABS, spota-labs.com is now online—designed and released early specifically for those interested in the 630m band. There is no risk in opening it, there is a SSL certificate. We’d love for you to stop by.
73, Chris and Paul (VK3HN)
Are you interested in getting a 630m transverter PCB? Take a look here: Project - Platform for creating and sharing projects - OSHWLab SORRY STILL OFFLINE BY BACKEND REVIEW AND TEAM HOLIDAYS
We assure you that we derive no financial benefit from this.
73 Chris and Paul
(post deleted by author)
Instead of a single mode or band, why not have a challenge where it only scores if the activator makes QSOs on more than one band.
Something like:
QSOs on 2 bands = summit points x 2, on 3 bands = summit points *3 etc
Perhaps also a minimum number of QSOs on each band to prevent the 1 QSO on 2m syndrome.
From a single summit, during a single activation, make contacts on a very low band and a very high band. The wider the gap between your lowest and highest band, the bigger your multiplier.
Forgotten bands (LF/MF, 160 m, 80 m, 10 m…) and microwaves score points. The usual HF bands score nothing, so they can still be used to qualify the activation, but they don’t count toward the challenge.
A yearly bingo card rewards activators who explore every band group in every mode.
| Band | Points per QSO | Reference frequency (MHz) |
|---|---|---|
| 2200 m | 50 | 0.1365 |
| 630 m | 25 | 0.475 |
| 160 m | 8 | 1.85 |
| 80 m | 4 | 3.6 |
| 12 m | 3 | 24.9 |
| 10 m | 3 | 28.5 |
| 6 m | 3 | 50.1 |
| 2 m | 1 | 144.3 |
| 70 cm | 1 | 432.2 |
| 23 cm | 6 | 1296.2 |
| 13 cm | 6 | 2320.2 |
| 3 cm | 6 | 10368.2 |
All other bands (60, 40, 30, 20, 17, 15 m…) score 0 points.
The reference frequency is an approximate band centre. It is only used to compute the span multiplier (section 3), so you don’t need to log your exact frequency.
There are only three mode categories, and they are used everywhere in the challenge (scoring and bingo).
| Mode | Includes | Multiplier |
|---|---|---|
| CW | CW | ×1 |
| Voice | SSB, AM, FM | ×1 |
| Digi | FT8, FT4, RTTY, PSK, and other digital modes | ×0.5 |
For each activation, take the lowest and the highest band where you made at least one complete QSO, and compute the ratio of their reference frequencies:
Ratio = f_max / f_min
The multiplier is 1 plus the number of decades (powers of ten) covered, capped at ×5:
M = min( 5 , 1 + round( log10(Ratio) ) )
| Ratio | Example | Multiplier |
|---|---|---|
| ~1 to 3 | single band | ×1 |
| ~10 | 80 m + 10 m | ×2 |
| ~100 | 80 m + 70 cm | ×3 |
| ~1 000 | 160 m + 23 cm | ×4 |
| ≥ ~10 000 | 2200 m + 23 cm | ×5 |
For each line of your log (one band, one mode):
Points = Number of QSOs × Band points × Mode multiplier
Then for the whole activation:
Subtotal = sum of Points over all lines
Activation score = Subtotal × M
A valid SOTA activation still requires at least 4 QSOs in total (on any bands).
| Band | Mode | QSOs | Calculation | Points |
|---|---|---|---|---|
| 2200 m | CW | 1 | 1 × 50 × 1 | 50 |
| 80 m | Voice | 4 | 4 × 4 × 1 | 16 |
| 23 cm | Voice | 3 | 3 × 6 × 1 | 18 |
The bingo card is a 3 × 3 grid, filled throughout the year across all your activations.
| CW | Voice | Digi | |
|---|---|---|---|
| 2200 / 630 m | |||
| 160 / 80 m | |||
| 23 cm and up |
Bingo bonus = Number of completed lines × 300 + (2 000 if all 9 squares are validated)
There are 8 possible lines (3 rows, 3 columns, 2 diagonals), so the maximum bingo bonus is 8 × 300 + 2 000 = 4 400 points.
Yearly score = sum of all activation scores + Bingo bonus
I think the reason that I don’t feel attracted to that suggestion, Colin, is that it seems to value quantity above quality. Looking at past challenges, they have all presented the opportunity for high value contacts on bands or modes that have been neglected. In your suggestion, given a multiband rig and agile antenna such as an end-fed or W3EDP with a simple tuner and you can roam easily across several bands without leaving your rig, the challenge element would be staying put long enough to log contacts on all these bands.