[Milsurplus] Re: Late version of BC-366

[Bob Camp]

Hi

To add a bit......

If they really were running repeaters with enough capacity and  
durability to be a primary communications system - where are the  
filter banks, the change over relay banks, and the dedicated control  
gear. You could probably throw custom antennas into that list as well.

All of that stuff should be running around in fairly significant  
quantities. There was a *lot* of traffic on HF in Europe, and it was  
over ranges that would have required multiple VHF repeaters. The gear  
would have had numbers, design documentation, field trials, and all  
the other stuff to go with it. It would have taken significant  
support activities to coordinate it all. All of that would have left  
a "paper trail".

A lot of people have made repeaters by plugging radio A into radio B.  
It does work, sort of, with the right radio and frequency setup. To  
make it work all the time, with a range of frequency pairs, and any  
radio in inventory is a whole other story. Making it work over  
multiple hops is even more complex. The radios available were not  
designed for repeater use - transmit duty cycle and an number of  
other things are very different in a repeater.

Did they have airborne repeaters? I'm sure they did. Lashing up a  
couple of radios in an otherwise junk aircraft to extend the "ears"  
of a single poorly situated tower with a mission coming back makes a  
lot of sense. The time slot involved would have been only one or two  
hours. They certainly had the ability to do that sort of thing  
quickly and easily. It probably worked well enough / often enough to  
be worth the effort with the airborne end right over the field. Once  
one outfit did it, I'm sure others copied the idea.

Repeaters with AM are not as easy to do as they are with FM. The  
capture effect on an FM radio helps a lot. I suspect that the whole  
repeater thing would have made more sense if we had not been running  
VHF AM ...

Bob
KB8TQ



On Sep 23, 2007, at 8:58 AM, David Stinson wrote:

>
> ----- Original Message ----- From: "Unserviceable but Repairable"  
> <cosmoline at aa4rm.ba-watch.org>
> Subject: [Milsurplus] Late version of BC-366
>
>
>>> Fact that SCR-522 stopped hf command radio in Europe seems generally
>> accepted.  Hence "VHF COMMAND" label obvious
>
> Sorry, Marty- as has been posted here several times,
> the "VHF only" theory, although "generally accepted," is  
> absolutely, demonstrably, and documentedly wrong.
> One mode did not exclude the other. Both modes were in service and
> both were used for many years even after WWII.
> Many aircraft had one or the other set.  Many had both.
> It depended on operational location and mission,
> and what equipment was available at the particular time and place.
>
> I've heard this "VHF repeater" story many times.  Enough times to  
> convince me it was at least tried and maybe implemented somewhere.
> There are mentions of it and apocryphal stories about it, but there  
> is no conclusive evidence that it was ever fielded as the primary  
> aircraft communication system
> in Europe or anywhere else.
> To the best of my knowledge
> (and if I'm wrong I'd sure like to hear about it),
> to date, not one training manual,  not one mention in any log book,  
> not a single piece of operational paper, such as inclusion in a  
> Radio Operator's Information File, exists anywhere.  If this were  
> *the* primary comm mode
> in Europe, we should have lots of accessory parts and materials and  
> books marked for the "VHF repeaters."
> Where are they?  I haven't seen any, and I've been collecting this  
> stuff for forty years.
> I've not seen a single photo of radio techs working on this
> complex VHF lash-up, yet I have lots about HF; you'd think  
> operating and maintaining such a VHF set in WWII would have  
> required extensive training for "90 day wonder" radio mechanics, so  
> where are the training docs?
> We have them for SCR-274N and SCR-287, lots of them.
> There may be a manual somewhere on the hook-up of two ARC-1 sets as  
> a repeater, and I think someone had something technical on two  
> SCR-522s,
> but neither of these prove when and where this may have been used.
> Yet we have dozens and even hundreds of documents, log books,  
> training manuals, flight sectionals, training and operational  photos
> and Radio Operator Information Files telling us that HF was not  
> only used throughout the war, but was indespensible to operations  
> in every theater.
>
> I don't mean to "jump on" you, Marty.  You're not alone in this  
> "VHF took over" idea, but I honestly don't understand
> why some of us, after all this has been proven beyond doubt,
> continue to hold this mistaken belief. Sometimes, I feel like all  
> the research I've done and shared here
> just goes straight into the bit bucket.  It's frustrating.
>
>
>
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