[amsat-bb] Re: AO-7 mode A experieces from KP35

Bob- W7LRD w7lrd at comcast.net
Fri Oct 8 15:06:16 PDT 2010

Hello Mika and AO-7 fans 

I to have made many attempts at AO-7 mode A.  These efforts go back to the days of RS-15.  I have noticed that my HF antenna for 10M is a 4 element cubical quad.  It is cut for a frequency much lower in the band.  As a result the reflector seems to act more like a director at 29.45Mhz.  Therefore  signals are better off the back of my quad than the front.   From Seattle Wa. CN87 I have made several attempts at JA contacts.  Only one time I was able to copy a partial call from JA.  Local U.S contacts are not a problem.  When it comes to stretching the footprint that's where the "fun" begins.  Mode A I think requires a bit more uplink power.  If we ever get more sunspots propagation on the 10 meter  gets interesting.  I believe it was RS-13 that had a 15M uplink and a 10M downlink.  You could work it at times way byond the horizon.  Ahhh the "good" old days!  Mika, send me note from time to time if you want to try a mode A attempt.  We have done it many times on mode B.  Good luck. 

73 Bob W7LRD 


----- Original Message ----- 
From: "Mika Siira" <oh8mbn at suomi24.fi> 
To: amsat-bb at amsat.org 
Sent: Friday, October 8, 2010 2:09:44 PM 
Subject: [amsat-bb]  AO-7 mode A experieces from KP35 

Hello folks, 

I have been mostly mode B user on AO- 7 satellite but 
today I decided to try mode A  from my summer QTH. I have two 
for downlink (vertical and Spiderbeam with four elements for 28MHz) and 
no problems for receiving signals from the sat. Of course because of 
the polarsation change switching between these antennas during the pass 
gives best results. 
For the uplink I have used FT-817 (5w power) to 9- 
element yagi, unfortunately SWR is high above 145MHz. On every pass   
that I tried today I have heard my own signal on downlink (weak but 
What is the recommended power level for mode A (if there is 
one)? From my previous visits to my summer QTH I have heard some 
japanese stations and satations from stateside, so this mode would be 
worth to try. On mode B from my city location 
5-15 watts is well 
enough. What kind of antennas people are using on mode A? 

Mika, OH8MBN 

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