[TenTec] Re: Tentec 6N2 Questions

[Allan Henry Kaplan]

There simply is not room to mount any parts on the rear panel of the 526 - the rig is too compact for that!   And yes, the radio uses a (transformerless) "bridge" output audio amplifier IC with two hot leads to drive the internal speaker.     There is no direct external access to the speaker circuit, sothat the back-to-back Radio Shack transformers that Al mentioned will not help here.   

The front panel headphone jack is "isolated" from the speaker circuit by resistors, so that grounding an output lead should not harm the AF output IC.   This jack will not drive a speaker.   The easiest way to use an external speaker would be to connect the AUD OUT phono jack (rear panel) to an amplified speaker.  These are used as accessories to some computers, and are not expensive.   

The bridge-output AF IC gives the radio a fair amount of bang for the buck and is similar to the parts used on Pegasus and Jupiter.    Staying with previously used circuitry, when appropriate, reduces engineering development time and radio price.  An output transformer would take up some scarce space in the box.   Mounting and paying for a custom transformer were not recommended by the design team because there was no perceived advantage for the intended use of the radio.   Complaints about not being able to ground a speaker lead prompted Ten-Tec to use a different AF output IC on later radios.  

The 6N2 is a good value for a two-band multi-mode transceiver.   73, Allan, W1AEL (retired from ten-Tec engineering)