just purchased a very nice looking sonar fs-2340 off off of e-pay. the pics and description of it shows it should be a very nice radio, have been wanting one for a while, always liked the construction of the sonar radios, i sold a model g earlier this year with the external meter, ( wish i hadnt) . now if the shipping dosent do ant damage, and everything is as described i should enjoy it when it arrives, got to love those tube radios,,,,,,,,,,,, jimbo
here in chicago we have a guy that goes by the handle of mark 3. He bought out some of what was left of sonars inventory after they went under. He still can build a brand new FS-2340 he knows those radios inside and out and can make them sound the best out of anyone else. Those sonars are tanks almost indestructable. hope you enjoy it.
Post by Tombstone (R.I.P.) on Dec 27, 2010 21:40:27 GMT -5
Rifleman is right about using a Demco modulator on your Sonar but use an unamplified mic. If you use a tug8 you'll be putting an amplified audio signal into an audio pre amp, then into the audio stage of the radio which means that you'l be pre amping a pre amp, which will result in massive overmodulation and you might not be able to control it unless the mic and modulator are both almost turned way down, almost off, defeating your purpose. You can either use the modulator or the amplified D-104 but not both. If you set up with both, you'll see what I mean.
Even with the stock hand microphone you could get 100% modulation out of the FS series of radios.
All you need with the Sonar is a mic audio wire, a ground (shield) wire, and a keying wire for the relay. If all you have are amplified D104's, you can always temp. bypass the mic amplifier board under the mic.
Tombstone is right... NEVER hook an amplified microphone up to a Demco modulator... UNLESS you don't want people to understand what the hell you are saying !!! LOL !!
Remember to NEVER use a Demco modulator on a RADIO that has a transistorized mic amplifier in it. The voltages coming out of the Demco WILL burn the transistor out !!
Also, one of the quirks that the FS-2340 has is (2) boards were addied to this model to meet FCC standards. An Audio Clipper/Filter (if you look at my FIRST photo of the top view (008.JPG), it is the square board on the left side), and a Low Pass Filter (same photo, it is the board hanging over the power transformer).
Back "In The Day", a lot of people would BYPASS (NOT REMOVE)these boards to get more out of the radios. Then hook them back up when they sold the radios.
Last Edit: Dec 28, 2010 14:09:46 GMT -5 by rifleman
I also know this post are quite old but i had a tech put two bypass switches for power and audio circuit . can use it like regular or lower the power and increase audio and tie in my tube type amp with a d 104 tug 9 mic . All my feedbacks have been great audio and modulation clear as a bell ..great radios .
its a funny thing. this thread is almost 7 years old! and with all of lifes changes in the past 7 years. im right back with a different sonar fs2340, and a demco modulator. getting them set up this same way again. i really appreciate this forum. some of the people are gone. (r.i.p) but there helpful, friendly ways and knowledge live on!