[Milsurplus] Question on A/C fixed antenna

[Robert Downs]

And a hard copy is available at www.wa5cab.com 

 

Robert Downs

 

From: milsurplus-bounces at mailman.qth.net [mailto:milsurplus-bounces at mailman.qth.net] On Behalf Of Jim Whartenby
Sent: Wednesday, July 3, 2019 12:23
To: Military Surplus Mail List
Subject: Re: [Milsurplus] Question on A/C fixed antenna

 

PDF of "Airborne Radio Equipment Handbook". 1943 can be found here:

https://cdn.shopify.com/s/files/1/1343/9895/files/Airborne_Radio_Equipment_Manual_1943.pdf?

Nice resource, thanks Mike!

 

Other aircraft related manuals can be found here:

https://aeroantique.com/pages/downloads

 

Jim

 

 

I wonder why people argue over the 10% of their differences and ignore the 90% they agree on?

 

 

On Sunday, June 2, 2019, 8:39:45 AM CDT, Michael Hanz <aaf-radio-1 at aafradio.org> wrote: 

 

 

I might respectfully suggest that the question might be better worded as the internal fuselage run length of the HF antenna to the transmitter.  All of the large WWII US aircraft that I'm familiar with used antenna relays which provided the receiver with a signal almost as an oh by the way issue.  You'll see a lot more effort put into keeping the antenna lead short to the transmitter, not the receiver.  That makes sense, since you have a lot more trouble consistently loading a transmitter with long lengths of bare (or bead insulated) transmission line running all over the place.  The receivers pretty much worked fine with whatever insulated wire it took to get from the antenna relay, and routing in the various photos I have don't seem to show a lot of the care devoted to the transmitter lead-in.*  

*(That all changed with the end of the war, prompted by the requirement for using coax for the VHF sets earlier in the war.  Except for the legacy AN/ARC-8 set, postwar HF sets evolved into coax to a generally  remote antenna tuner.  That made the HF antenna connection very short and freed up options for transmitter placement within the airframe.)

I can't suggest a more graphic depiction of the relationships of transmitter to antenna than in the Airborne Radio Equipment Handbook (April 1943) pages 57 through 68.  For example, below is the one for the B-24.  You can see the relative positions of components and roughly estimate distances from previous aircraft dimensions in the handbook.

 - Mike  KC4TOS

On 6/1/2019 4:17 PM, Hubert Miller wrote:

The leadin from the fixed antenna on large U.S. aircraft such as B-17, PBM, PB4Y, PBY – how long was the run of the internal leadin, from its entrance to the airframe to the 

radio receiver? In general ?



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