[TenTec] 566 v3.028

[Richards]

I would not be surprised if the 707 would benefit from a very light 
preamp.   It would not take much to boost it going in, and then pare 
back HW Gain and mic input levels on the rig to where they should be. 
It is not a fault of either mic or rig, really.   This happens all over 
in the sound recording arena, also in any live music scenario.

I an provide some simple schematics for this, or suggest some small, 
inexpensive pre-amps if you like.   While it may gall you to spend 
another, oh... $45-90 on a nice little preamp, it can be the right tool 
for the job in many cases.   I often use a dynamic mic with low inherent 
open signal voltage with an inexpensive preamp, and then use the Line-In 
input on the rig - I feel it is cleaner.   The rig has a preamp built of 
sorts built into the mic input circuit, and a high quality external 
preamp on the Line-In input is often a cleaner, more robust signal in 
the end.

Parenthetically, I use the M-Audio AudioBuddy preamp in my shack for two 
purposes:   one mic routes a mic to the transceiver, while another line 
routes another mic to my computer for speech recognition software.  It 
cost me $70 (typical street price, sometimes higher or lower 
depending...)  and I have used this for near 10 years in this and other 
capacities, usually with home recording  (I play guitar.)

I like it plenty, but there are less expensive products that do the same 
job very well for less cost.  Some guys use a small recording mixer 
which contains just such a preamp, and they use it for more functions 
than to mic a transceiver.   I have used a similar arrangement to route 
both microphone input at line level AND play computer sound files at 
line level, as an ersatz voice-keyer, so I can use the computer to call 
CQ during a contest, even when I am not doing that through a logging or 
control program such as N1MM which has facilities for this.   That way, 
I can log on one computer, using one program, and play voice keyer with 
another, and so forth.

Just MY take. . . .

=========================== James - K8JHR  ===================



On 4/5/2012 9:14 AM, Rsoifer at aol.com wrote:
> Thanks for the info guys, but RF feedback is only part of the problem.
> There is still audio distortion caused  by having to run the mic input and H/W
> mic gain at too high a level (with the 707 mic).  I didn't have that problem
> with v2.041XT, nor do I have it with v3.028 and the 706 mic.  I'd still
> like to be able to use the 707, though.
>
> 73 Ray W2RS
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