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Title: VERY INTERESTING VIDEO OF KFI AM RADIO SITE-QIX-REA MOD MONITOR IN USE Post by: W2PFY on January 15, 2018, 02:47:47 PM I found this 1/2 hour video to be very interesting. One of the comments were on a new transmitter where you can see the thing making about 30KW on average but only goes up to 50 KW when people aren't talking. That to me would be a very interesting thing to do with ham transmitters. You could be running 200 watts on 40 meters and go up to 1500 when you shut up if that's possible? I guess it would be the reverse of the old
control carrier screen grid system from back in the day. They also had one of Steve's REA modulation monitors in use with some interesting comments about it. Hats off to Steve once again! That mod monitor is seen at about 19.05 on the video. https://www.youtube.com/watch?v=Qnvmf8mPUW8 (https://www.youtube.com/watch?v=Qnvmf8mPUW8) Title: Re: VERY INTERESTING VIDEO OF KFI AM RADIO SITE-QIX-REA MOD MONITOR IN USE Post by: K6JEK on January 15, 2018, 04:00:14 PM Modulation Dependent Carrier they are running with the Nautel NX50 It's like my Drake T4x running controlled carrier except upside down. Maybe a little fancier. How long can it be until Steve designs a class E transmitter and modulator with this?
REA monitor at 19:08 Title: Re: VERY INTERESTING VIDEO OF KFI AM RADIO SITE-QIX-REA MOD MONITOR IN USE Post by: Opcom on January 15, 2018, 06:57:48 PM There are specs in the transmitting tube manuals for this kind of thing where modulation is essentially negative.
example: one page from TT-3 on the 852 100W Triode, in the "RF Power Amplifier and Oscillator - Class C Telegraphy" section: http://bunkerofdoom.com/tubes/tt3/00115.jpg "Modulation essentially negative may be used if the positive peak of the audio frequency envelope does not exceed 115% of the carrier condition" Title: Re: VERY INTERESTING VIDEO OF KFI AM RADIO SITE-QIX-REA MOD MONITOR IN USE Post by: WA2SQQ on January 15, 2018, 07:45:13 PM That’s a great video, thanks for sharing. It’s also a nice ad for the mod monitor. So I knew 3 broadcast engineers, and all three lost most of their hair. The Sr guy in this video seems to be similar.was it due to all that RF?
Title: Re: VERY INTERESTING VIDEO OF KFI AM RADIO SITE-QIX-REA MOD MONITOR IN USE Post by: W2PFY on January 15, 2018, 09:54:47 PM Quote ["Modulation essentially negative may be used if the positive peak of the audio frequency envelope does not exceed 115% of the carrier condition" Quote Yes Patric, I have seen that once before and only once? I am not and engineer but it sounds like double speak to me? Maybe an engineer can explain that to me ??? ??? Please help, I am stuck in this quote box! |