Original U.S. WWII Boeing B-17 Flying Fortress Bendix Radio Loop Antenna Type MN-20E
Original Item: Only One Available. This is an unissued totally original Bendix MN-20E loop antenna for use with the MN-26 and RA-10 receivers of Boeing B-17 Flying Fortress Air Craft during and after WW2. It was mechanically rotatable via splines on bottom. Measures 5" x 10" base, 9" loop, NOS.
Nicely marked on the base:
ROTATABLE LOOP UNIT
SER. NO. I-31771 WEIGHT 5 LBS.
BENDIX RADIO DIV. OF BENDIX AVIATION CORP.
BALTIMORE, MD. U.S.A.
Until the prospect of amateur work being possible below 500kHz, inclusion of any of the navigation receivers seemed to be inconsistent with the general rule for the fight deck - "Everything should be useful, at least in some fashion." If I keep my weight down to a 96 pound weakling or really "suck it in", just enough room is left in the entry gap into the octagon shaped array of racks to accommodate a vertical column of the most common manual and automatic direction finding receivers used during the war. These receivers were teamed with loop antennas and not only found application as radio range beacon receivers, but also functioned as independent direction finders on signal sources whose position was known, such as AM broadcasting stations. Often the aircraft had both kinds of receivers, one of those depicted here and an MF command receiver such as the R-23/ARC-5 or BC-453 to handle the radio range system. That allowed cross checking bearings (at least where the radio range was established), though in the vast reaches of the Pacific or in forward battle areas of either theater, the larger receiver was often the only one providing any accuracy. The control boxes for these receivers are mounted to the right of the bay.
The Bendix RA-10 was a dual purpose receiver. It actually doubled as both a navigation set and an HF receiver, teamed with the TA-12B transmitter just out of view to its right. The frequency range of this particular set (an RA-10DB) is 150-1,100kHz and 2.0-10.0MHz. The antenna is shown at the bottom of this page, a manually steered loop that (at least in the AAFRadio shack) is shared with the MN-26 receiver below it.
The Bendix MN-26 receiver came in a surprising number of variations. Though all similar in appearance, different frequency ranges were available for different theaters, leading to a frustrating time trying to match the control head with the receiver. For instance there was an MN-26LB, that had bands of 200-410kHz, 550-1,200kHz, and 2.9-6.0MHz. It is the one peculiar version of the MN-26 series that is also known as the AN/ARN-11. Perched on top is a small ferry beacon receiver, employed with the radio range system in aircraft that needed to be moved from one place to another but had yet to have a radio compliment installed. This was fairly common during the time when the destination of a particular aircraft out of the factory could be either the European or Pacific theaters.
- This product is available for international shipping.
- Eligible for all payments - Visa, Mastercard, Discover, AMEX, Paypal, Amazon & Sezzle