> Adi Linden <[EMAIL PROTECTED]> wrote: > I finally had a chance to play with the > Mitrek and radio again. I took the > advice and tuned the Mitrek per Motorola > spec, 120W out if I remember correctly. > This made all the difference! There is > no longer any difference between antenna > or 50 Ohm load connected to the radio.
This is the expected result. > There is no longer any significant difference > in duplexer tuning any longer. Once the > duplexer has been tuend for maximum pass > using the signal analyzer I cannot improve > upon it once the transmitter has been > connected. Did you place a meter in line from the transmitter output and the duplexer and tune for min reflected power with the duplexer properly terminated into a 50 ohm load? > It seems that a cable length of 61 inches > is almost ideal between the radio and the > duplexer. If you use the above method, any practical cable length should work pretty well. If you don't there will be a modest amount of reflected power which results in heat. > It results in about 1.5 dB loss thru the > cans. Insertion loss, adjustments for said are possible on most cavities, even the square motorola T-1500 bottles. > The 1.5 dB were calculated by comapring > the power into a 50 Ohm load with the > transmitter connected directly versus > power into a 50 Ohm load with the duplexer > connected. Part of the measurement without the bandpass cavities might have included sideband products. > PA current changes by only 100mA when > the transmitter is connected to the > duplexer. Very happy output transistors operating in their designed saturated mode. > Thanks, > Adi cheers Adi, skipp Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
