In message <a12210a3-bdb4-4c00-5da4-23e9fe78920e@...>, Alan G3WXI aka G8AGQ <strongmra@...> writes
Good Evening Brian
Brian Howie GM4DIJ wrote:
I got mine 2nd hand in the late 90s. I've just fired it up on 4m for a sked. I only really use it for 4m and 6m these days and as a 432 MHz IF for 13cm and 9cm. I do use it for general coverage receive on SW and VHF/UHF. Some day I'll get? it back onto TopBand, which is the only SW band I'm interested in.
The only faults I've had are the notorious on/off switch, the CW key socket coming loose off the board? and a 21MHz fault due to a blown band switch diode.? I did the high power capacitor? mod for 4m while I was fixing that one. I also replaced the? hard wired battery with a holder too.
Brian? GM4DIJ
I too am a long time 847 owner, having bought mine used around the change of the century from an old timer in ill health (as I am now) and I am writing to you regarding your reference to 4M conversions.? I sent my 817 to ML&S to have the Power switch replaced about 8 years ago and asked ML&S Service manager about the pros and cons of the 4M conversion, but he was not enthusiastic!
But as the years pass, I am seeing more and more instances of conversion!
I was using 4M way back on 4M PMR and a range of Microwave Modules products. Meanwhile my 4M equipment consists of a converted PMR Mobile and an Eastern European transverter but it would be nice to have 4M on my FT847!
Your comments would be appreciated!
73s - Alan S, G8AGQ/G3WXI
Hello Alan,
The mod I did was the removal of one capacitor C5051, PA1O's modification and the snipping of the ALC line. There are other ones,that require changing more components and one that involves putting a small ferrite core into one of the coils. I tried the latter but I wasn't happy with it in terms of improvement.
I didn't add the RX preamp since the external PA I use has one. I can now get 65W out barefoot on 4m and the efficiency is much improved. 6m output is much the same. It means I can drive the external PA properly.
I started out on 4m in about 1975 using a converted Murphy lowband PMR valve rig as a transverter, then a Meon plus a Pye A200, which I also used when I got the 847. The 10W was just about enough to drive it, and I needed an external rx preamp. I recently modified a 50MHz TE Systems linear to 70MHz , but found it needed about 12 to 15W to drive it. Hence the mod to the 847.
I've not found a down-side to the mod. There's no sign of unwanted spurii.
Someone else might want to comment.
73 Brian GM4DIJ
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Brian Howie
Brian Howie GM4DIJ