[MRCG] BC-611 Parachute Portable w/Longwire Antenna

[willi6 at starpower.net]

Mark, 
  
I dug into the SCR-585-A Manual to see what Uncle Sam did back in WW-II. 
  
Sadly, there is no specific information on the "Glider Antenna" other than that the lead-in wire from the antenna to the radio should avoid any of the metal in the glider frame.  If it was the typical cockpit to tail longwire, depending upon glider type, it could be 15-20 feet on a small 2-Seat trainer, to about 40+ feet on one of the longer WACO variants.  
  
It also notes, that the glider frame is the "ground" to which the BC-721-A radio and adapter "GND" is connected. 
  
However, the schematic and narrative did add a clue or two regarding harnessing all that POWER from the BC-611 and getting it to the long wire antenna on the glider.  The "modification" is a 4-75 mmfd variable capacitor connected in series with the collapsed BC-611 whip and the glider antenna.  For tuning purposes, they used an external RF mA Meter (0-50 mA or 0-100 mA) between the radio adapter connection and the long wire antenna.  Tune for Max RF.  I suspect a #47 lamp might do the same thing. 
  
For the minutia lovers, the variable capacitor is C-33, P/N 19A35911, MFR - Radio Condenser Company, Camden, NJ. 
  
Happy Landings! 
  
73,  Dave 
  
Dave Williams - K7HMP/4 
Stafford, VA 


----- Original Message -----


   4. Parachute Mobile AM mil surplus radio jumps on Sat Oct 11 
      2014 over Byron CA in conduction with PACIFICON ARRL conference 
      (Boeing377 via MRCG) 
   ---------------------------------------------------------------------------------------------------- 

Date: Tue, 16 Sep 2014 18:52:06 -0400 
From: Boeing377 via MRCG <mrcg at mailman.qth.net> 
To: mrcg at mailman.qth.net 
Subject: [MRCG] Parachute Mobile AM mil surplus radio jumps on Sat Oct 
        11 2014 over Byron CA in conduction with PACIFICON ARRL conference 

We are going to try again for Parachute Mobile HF AM contacts using a BC 611 aloft on Saturday October 11, 2014. I will exit at about 13,500 feet and deploy my chute within about 5 seconds to give maximum hang time for QSOs. This time a trailing wire antenna should give us a better transmitted signal compared to the stock telescoping whip used last year. More details will follow as Pacificon approaches. 

Any ideas for antennas other than a trailing end fed long wire? It will need to be be jettisonable so I don't inadvertently drag it over any power lines if I have land off the DZ. 

Please stay tuned. 

73 
Mark 
AF6IM 
www.parachutemobile.com 

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End of MRCG Digest, Vol 28, Issue 13 
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