………Strange you should mention a composite outer casing, because I was just wondering if it would be an idea to replace the one on the 817 with an aluminium replacement. Did you construct the casing yourself or buy it somewhere?
Regards Steve GW7AAV
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Hi Steve,
As for home-brew rig casings, much time and effort has been expended here, reducing the weight of rigs for remote /P work since the mid 80’s. I started with a CIR Astro 200 (5 band, 12V-100W, HF/M) using folded 26 SWG & 24 SWG alloy sheet to replace steel, an FT77 using 3mm honeycomb composite and a Yaesu 4m FM PMR, using corrix board. The CIR was further lightened by first removing all the PCB’s and punching 87 one-inch diameter holes in the internal steel chassis, then adding-back the screening with aluminium foil. I also rebuilt the thick steel PA box in an otherwise relatively lightweight FT747, using alloy.
The IC706 2G was the most difficult and it took a week of work because the bottom casing is not straightforward but has a compound shape in the form of a bulge. Into this projects internal components. The top was made in 3mm honeycomb composite, with added screening. It accommodates the speaker and cooling holes. The bottom was re-manufactured in 0.4 inch thick two-skin epoxy honeycomb used in aircraft floors / bulkheads etc. This was internally ‘relieved’ to clear the circuitry, screened with self-adhesive aluminium foil to ‘pick up’ on the chassis; then meshed-over cooling holes were incorporated. Sure the rig’s a bit bigger now but using relatively thick honeycomb composite is a way of decreasing weight while retaining strength and some of the impact resistance. The combined weight saving over the conventional casings was 12.2 oz (347gm) as follows:
Standard steel top panel, 9 oz; new top 3.5 oz (both inc speaker).
Standard steel bottom panel, 8.5 oz (inc feet & prop-up frame); new bottom 1.8 oz (no feet or prop).
There were further savings as a result of a modified power lead (incorporating rev-pol. protection and a resettable circuit breaker) plus the fact that a CW key (if it’s worthy of the name) is incorporated into the mic case.
I have not considered mods for the 817 as it is not yet a year old. As is normal, Yaesu have fitted a steel case, presumably on the basis of material cost and ease of manufacture but there’s the attraction of relative simplicity in this casing, apart from clearance for the battery box etc. At least the internal chassis is cast in aluminium. However, the 817 is a lot smaller than a 706 so I could not see savings greater than perhaps 5 or 6oz. I can’t see that any high-tech composite approach would be worth the bother on an 817 but around 26 SWG (or thinner) bendable alloy might be worthy of investigation.
Any small weight saving (especially when added to many others) is worth the effort if the time and materials are available. I for one, have ‘groaned’ many times after seeing ‘boastful’ ads for the latest compact all band-all mode rig without my first interest, a weight figure given in the short-spec. I groan even more loudly when I buy one, take it out of the carton, rush it into the workshop and run a magnet over it! It’s been frustrating that for 2 decades nobody sold what I wanted forcing me to invest 200 hours on a home-brew 10W, 3 band SSB/CW HF rig with low receive current and 1.8kg. Until the 817, I don’t think it crossed the designer’s minds that someone might actually be taking their compact rig out of the car to be so cruel as to stick it in a rucksack and lug it across the Cairngorms or down a cliff.
There are expeditions where weight is not particularly important, except perhaps to comfort. In others, it’s central to getting the job done.
Weight saving applies to all equipment of course and it’s review should be an ongoing activity as technology advances. The first place to start is with battery technology. I never feel that I’m doing enough but one important (if low-tech) component of this overview is my own body mass, especially around Christmas time! All the meticulous, time-consuming effort in other areas does thankfully concentrate the mind somewhat in that particular direction.
Hope you succeed with the 817 case.
73, John G4YSS.
