On 20 Dic, 16:10, K3HVG wrote:
Scott Dorsey wrote:
They are heavy. I don't think it would be all that hard to convert them
to the new channel spacing (using a half-channel switch and reducing the
bandwidth), but I don't think anybody would want to, seeing how cheap
the modern UHF stuff is. And the military guys everywhere are trying to
get away from AM even for local ops stuff.
--scott

Well made points. The only add'l comment I'll make is that aviation
comms, those which will, at one point or another, be used in the global
ATC system will remain for the foreseeable future on VHF/UHF AM, albeit
considerable data is now passed via other modes/frequencies. The
airborne fleets are simply too big to convert, en mass, not to mention
the conversion of all ground-based assets. This subject has been
discussed at ICAO for a long time now and few appear interested in the
capital investment. I have a collection of some minutes and proceedings
from old RTCA meeting and symposiums in the 50's that present the idea.
Nothing is forever, though........... Finally, UHF has (like VHF did
a some time ago) gone from 100kHz spacing to the now standard 25kHz
spacing, or quadruple the number of available channels. Some have
discussed 12.5kHz spacing at meetings. The 12.5 spacing can present
some real difficulties with legacy equipment, though.
de K3HVG

Thanks to all.
It would make no sense using them in a ham radio station these days.
They are heavy, space wasting, power consuming and noisy (they have a
fan and electro-mechanical channel selection) and do not offer any
advantage as compared to modern UHF stuff.
Their destiny probably is dismantling, but so far I'm refrained from
doing this in front of such a sample of vintage radio and mechanical
technology. Mechanically they are pieces of art: all of the many
rotating mechanisms bear precision roller bearings (gears, shafts and
so). Indeed I dismantled completely a third one some 25 years ago, and
thas has been better than a workshop on mechanics and radio design. I
think I will save at last one as a future "historical" reference.
Best 73,
Antonio I8IOV