I was going to say that I always use 12.5kHz channel spacing but that’s on 477MHz UHF CB. That band seems to have made the switch from 40 channels at 25kHz to 80 channels at 12.5kHz channel spacing without much drama, but then of course the radios must be type-approved.
I was first licenced in the UK in 1981 and I well remember finding it difficult to get a word in edgeways on 2m back then, so changing to 12.5kHz channel spacing did make sense. But perhaps the urgency has gone out of it now that everyone’s gone to HF and/or FT8!
My Amateur rigs are all set up for 25kHz channel spacing. I think I might even have made a couple of SOTA contacts on 2m over the past 7 years The Amateur population density around here is so low that an activation on 2m and/or 70cm would only stand a chance of success if QSOs were pre-arranged, so channel spacing is a bit of a moot point.
Most modern 2m FM radios have a narrow deviation setting but AFAIK don’t have switchable 25/12.5 filtering. My VX170 in narrow mode drops the deviation down to be suitable for 12.5 spacing and also turns up the gain to make up for the fact that correct deviation for 12.5 will be quiet when received on a 25kHz radio. Similarly hitting the NAR button on an 817 set the deviation on FM suitable to 12.5kHz spacing.
Back in the 90s when buying and converting PMR/LMR surplus radios to amateur bands was de rigueur, there were loads of 25kHz surplus UHF sets as that band was moving to 12.5kHz. All the newer VHF hi-band surplus gear was 12.5kHz spaced, if you wanted anything for 25kHz you needed to accept things like Pye Westminsters and similar 70s designs etc.
Actually most modern amateur sets with narrow/wide FM switching have different IF filters for FM narrow and FM wide and sometimes AM if it is included. They are usually ceramic filters at the second IF (455 or 450kHz). The FT-817 and the VX-170 mentioned are good examples. Like many areas, there is very little traffic on 2m FM simplex where I live, so it is a moot point.
Thanks for the clarification Ian. It’s interesting that neither the 817 or 170 user manuals says they have switched filter widths for wide/narrow despite mentioning they change the TX deviation etc. After your post I had a quick peek in the service manuals to see there are two filters for the FM path for both units, I should have looked there first.
OTOH in the second menu number 30 gives a choice of eight different tuning steps, my rigs are permanently set to 12.5 Hz. Incidentally, while the V designations aren’t normally used around here, you do hear people saying things like “S26-and-a-half”!
Simplistic, Andy. When HF was made available to the “B” licenses the amount of activity on 2m had already dropped to a small fraction of what it had been in the 80’s, a time when a vertical beam rather than a colinear was almost an essential for FM. There was no sudden drop, just a continuation of the trend. Personally, I blame the roll-out of mobile phones!
Answer nothing… there is no licence requirement to use 12.5kHz spacing. For the reasons stated, the majority of people tend to use 25kHz spaced frequencies. I really like it when someone tells me they are using an old rig. Perhaps it’s just me… maybe a nostalgia factor is involved.
I have never had an issue with any of my rigs with the exception of an ancient Standard C520 that I used to own. When Paul G4MD and I were activating summits in Orkney in 2012, I tried to drum up interest on the Orkney repeater without success. I recall being told that the repeater was intolerant of 25kHz rigs and I wasn’t being heard. No problem with the 817 of course.
I have several pre-2000 rigs and all have been tweaked, but in response to the low mod comment, they have been set up as a compromise. The most amusing is my mobile set up which is a Trio TM-401A with 5kHz frequency switching. I can still get into the local net on 145.3625MHz with it.
I must arrange another Vintage Electric Handbag event to indulge your nostalgia! Special section for rockbound rigs (TR2200, TR3200, FT720G etc.). You can get a chance to give your TR-7010 a blast (how I regret selling mine now ). I’ve got a TR2300, FT290Mk1 and an FT 720G I could use!
Amazing you remembered that I have this rig. It is still in the shack hooked up to the BNOS linear ready for a bit of MS action when I have solved the antenna problem. I’m afraid Ofcom no longer want me to irradiate the upper rear portion of the house, so it is either move the beam higher or out to the middle of the garden, neither of which is visually acceptable… perhaps I could ask the XYL to move to the front bedroom.
Do my TS-711E and TS-811E qualify as electric handbags? Maybe too modern…
Isn’t referring to “S” channels like asking someone for 10 shillings instead of 50 pence. It’s just a simple calculation after all? It was only as recently as 1971 that the UK decimalised the currency…
The point I’m trying to make is, how do new Ops. gain confidence in their operating skills and move on from ft8 (other data modes are available) when they come across an “old timer” on 2m speaking an ancient foreign tongue? (2m mobile was my intro. into our hobby, as I’m sure it was for many others.)
I appreciate that vintage should be an exception, but if a station using a vintage 2m rig (unlikely) contacted me, they really should consider whether or not I would understand what they were asking me to do.
Has always been so Fraser and probably will always be. When I was first licensed in 1969 and having only been used to SWLing on HF, the crystal bound operation and split frequency working of 2m AM was a different ball game. Brian will no doubt agree.
Recently on an activation I requested a QSY from the calling frequency to 145.400. Back came the response from the novice operator, “aye S16, see you there”. It seems these old time designations just won’t die quietly.
By golly, yes! Call CQ in the band segment for your geographical area, and tune the whole band for a reply! CQs were loo…ong and the replies had to be just as long! Back in the 60’s little things like coax relays were hard to find and cost a second mortgage, so at first just a simple change from transmit to receive was a flurry of activity!
I first encountered ham radio in the late 50’s on Top Band AM (tuning down from the medium wave on a badly aligned Rx!) and could understand very little of what was said, but it intrigued me and I wanted to find out more. Are the new ops that devoid of curiosity and willingness to learn new things? Not in my experience!
Incidentally, I checked the other day and just in England there are 184 Foundation licensees listed in the all-time results as active in SOTA, so not all FLs are bound to FT8!
No, I’d made a one valve TRF from a kit and I didn’t now what the core in the Denco coil did so I screwed it out as far as it would go and left it. One night I tuned down past the Medium Wave and found someone talking with a Brummy accent, the rest is history! Oh, the next summer I played with the short wave band on the family receiver and discovered fifteen metres wide open to South America, dozens of PYs in armchair copy, that set the hook in firmly!
That brings back memories - when I was a teenager my father and I build a superhet shortwave receiver using Denco plugin coils. As I remember it the IF strip was pre-built and aligned and came from Henry’s Radio. It had one of those epicyclic drives to give it a degree of tuning spread but I later added a small secondary tuning cap to fine tune it.
I spent hours on that radio when I should have been doing homework !
The Amateur population density around here is so low that an activation on 2m and/or 70cm would only stand a chance of success if QSOs were pre-arranged, so channel spacing is a bit of a moot point.
). I’ve got a TR2300, FT290Mk1 and an FT 720G I could use!
