browning mark 3

[Rooster1227]

this mark 3 transmitter has had 2 tubes switched in chassis the 12ax7 tube is in the spot where the 12au7 belongs plus there is a knob added to the front ,if you put the tubes where they should be the radio wont tramsmitt why was this done?

[dirtyjob]

the 12ax7 has more gain than the 12au7 as to the knob on the front of your mk III it's hard to say what it was put there for, perhaps its a variable power control ????

[Rooster1227]

the 12ax7 has more gain than the 12au7 as to the knob on the front of your mk III it's hard to say what it was put there for, perhaps its a variable power control ????

I think you are right when you turn the knob to the right the ping is louder and the radio has more output what are the 2 switches on the reciever side for in the back it has one big toggle switch and one small one and has a toggle switch on the transmitter front that says slider on slider off

[dirtyjob]

i can only guess on what your switches do as they have been put there by someone... my "guess" would be that one of your receiver switches either shut the ping off and the other may change the length of the ping, these were a common modification so thats why im guessing towards this.
As far as the transmitter switch i again can only guess it's a 10 kc switch so you can transmit on the rc channels like 3a "between 3 and 4" and the rest such as 7a/11a/15a/19a accordingly try setting your transmitter to channel 3 and put the slider switch on and on your receiver tune to the rc mark between 3 and 4 and hit spot. ,note this is just my guess, if there is an rca jack or pigtail on the transmitter it may also be for the use of a vfo.