| Author |
Message |
    
Mayor513
Intermediate Member
Username: Mayor513
Post Number: 105
Registered: 3-2002
| | Posted on Thursday, June 08, 2006 - 8:44 pm: | 
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--Hi, all. I just got in my new Astron RS-70M today, and I hooked up the Texas Star DX350HDV to it. On SSB, 18 watts into the amp., the amp. will do about 275 or so and draw about 36 amps. However, when I get on AM, that is when the amp meter on the power supply goes backwards. The radio is set up to dead key 3 watts, and the PEP is 25 watts.
--With the radio in the AM mode, using the above power, the power output is this:
3 watts DK= 140 watts @ 24 amps (that sounds ok)
25 watts PEP= 290 watts @ 16 amps (????)
--My radio is an RCI-2950DX and I took the above measurements with the "Dial-A-Watt" feature in the "out" position. The SWR on the channel I was taking the measurements on was between 1.1 and 1.2, so, no problem there. The meter I used for the measurement is an Autek Research WM1 (set for PEP mode).
--It's weird why the SSB amperage seems legit (36 amps) while the AM "swing" is wayyy wrong. I wonder if the problem lies in my meter (which many people say the Autek WM1 is a very accurate meter), the power supply amperage meter, or could it be something in the Texas Star? Sorta disappointing to see that backward swing of the amp meter. Thanks for your help! |
Chad
Advanced Member
Username: Chad
Post Number: 912
Registered: 11-2004
| | Posted on Thursday, June 08, 2006 - 11:07 pm: |
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What antenna? Read the balun thread  Feedline radiation in the shack, mabye?
Chad |
Mayor513
Intermediate Member
Username: Mayor513
Post Number: 106
Registered: 3-2002
| | Posted on Friday, June 09, 2006 - 10:54 am: |
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--Hi. It's a Maco Alpha V5/8 omni. I asked a friend how my signal was on his S-meter, and he said I had good forward swing, so, I guess everything is ok. Like you mentioned, maybe RF is somehow getting inside of the PS and into the amperage meter. |
Moonraker
Intermediate Member
Username: Moonraker
Post Number: 210
Registered: 3-2005
| | Posted on Friday, June 09, 2006 - 8:42 pm: |
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Check your power in rms mode instead of pep. You will probaply find that at a 140 watt dk your rms power swings back with modulation. I like to dead key just low enough so that my rms power doesn't swing backward and maybe just slightly forward. Try about a 75 watt dk from the amp and see what happens. |
Hotwire
Senior Member
Username: Hotwire
Post Number: 1438
Registered: 1-2005
| | Posted on Saturday, June 10, 2006 - 1:18 pm: |
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I agree with moonraker, reduce the radios dead key so that the amp deadkeys somewhere between 50 to 75 watts and you will have the real nice audio of a 1 to 4 power ratio. 2 watts input into the amp ussually does the trick. |
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