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Belcom LS-707 70cm multi-mode rig
6 May 2015 | by A radio amateur in Nottingham,Vic G0RVA, recently bought one of these Belcom rigs. It appears to be an all-mode 70cm rig, although I am not familiar with this unit.
I know Belcom did a 2m version (the famous Liner-2, which I did once own) and a similar version for 70cm. The Liner-2 was a modification of their 10m version, which I don’t think was ever sold in the UK. Inside Vic’s rig was what looked like a canned preamp with the marking “AngleLinear” but again I am not familiar with this unit. Angle Linear appear to be based in the USA http://anglelinear.com/ .
In its day, the 2m Liner-2 transformed 2m. It was a synthesised SSB rig and was frequently pushed too hard so that splatter was a problem. I was amazed how far I could work on 2m SSB with 10W pep. From Cambridge I could work stations that would have been impossible on FM or AM. I found I could work 200-300km with a simple antenna under ANY conditions.
Many were critical of these early Belcom transceivers, but I enjoyed my Liner-2 as did many others. Later I bought an ICOM IC202 which was a better radio, but with less ERP. The IC202 had a mock military style, that really was not too clever.
The “coming of age” of 2m SSB marked the change from “tuning high to low” to single frequency working. Sadly, there is far less activity on 2m SSB outside of contests so people think VHF is only really any good for local QSOs. With 10W SSB, or even less, it is possible to work a long way on VHF irrespective of conditions. From my current QTH, I think 200km is reachable with 5W pep and a 3 el beam on 2m. It is not that different on 70cm where I use 5W pep and a 5 el beam. Both my beams are hand rotated.
One Response to “Belcom LS-707 70cm multi-mode rig”
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Hi.
I have the 2m version, the LS-202. It’s a handheld rig FM and SSB, using 6 AA cells as power, and “tuned” with three thumbwheels and a +5k switch, and a crude +- VXO facility.
At first, “the mick” was extracted profusely by my contempories, but on a contest, if someone wanted to hear what the oposition was doing, my 202 was for many the portable of choice when “going for a walk”… Also good for the off duty pub run, we could monitor our station, so if something happened, they could just call us back, not needing any extra radio in the main tent etc.
Initially it was very deaf, but with a bit of deft tweaking using a weak signal as a test, it came up nicely to rival (or even better) many of the other radios of the time for sensitivity at least, needing no more than the front end and IF can’s peaking.
On SSB, there are very few stages between antenna and speaker on RX, so the lack of no signal noise is welcome, I found it great for beacon checking from hiltop’s. If that could hear it, the path was open!
On FM it works like any other handie of the day, just that it eats batteries as of course it’s still using a class AB linear PA stage, at all of 1 Watt out, still, with a homebrew LDO regulator set to 10V powering it via the charge jack (batteries removed) it was suprisingly good for mobile work too with an external audio PA, and headset mike, as I had a very noisy vehicle.
I did find it was possible to squeze more power out on TX, but the spurious and harmonic contect got “interesting”, so I put it back at the 1W level.
My 202 has issues these days, having been dropped and abbused (that mobile setup also vibrated more than most) but it can still work well when wanted, though “tuning” for contacts with three thumbwheels and a +5k switch is “tedious” at best.
If the 70 cms version is just as usable, a great little rig to have about when you just need check something…
73. Dave G0WBX (G8KBV)