National nc-183d As audio monitor

[kc2etm]

Hi i have a nc-183d that i would like to use with headphones to listen to my outgoing audio
But my question is where to set the tone control to get a true idea of my sound it Seems that control makes a large difference from tinny and thin to muddy and boomy

[KA0HCP]

"Eleven"

[AJ1G]

Any receiver used for over the air audio montoring will work after a fashion, but all will add  'coloration" to what you are hearing due to the IF bandwidth, possible front end overload distortion, setting of the tone control as you mentioned, and the inherent distortion of the audio amplifier of the receiver.

A better way would be to use a simple audio monitor that samples RF directly off the feed line through a volatage divider, into a simple small signal diode detector, and then  to a good quality amplifier driving the phones or speakers.

Im currently using a 100 to 1 volatge divider made from a 10K and 100 ohm resistor fed through a coax tee at the output of the wattmeter feeding the antenna, into a small signal diode, the output of which goes into an aux input channel of the duty stero system in the shack.  Gives very clean and essentially unlimited audio bandwitdh output into the amplifier.  There are a few threads here in Tech Discussion on this subject on how to make such a monitor.  One thing to watch out for, keep the voltage divider sample point as close as possible to the feed line, I originally fed it through about 8 feet of RG-58 into the tee at the feed line and the coax "side branch" reactance seriously messed up the loading  and tuning of my HT-37 on 15 and 10 meters.  No problem through with a very short piece of coax into the divider at the tee.

[W3GMS]

Here is a very good thread on the topic of monitoring ones audio.  Everyone should build one!

http://amfone.net/Amforum/index.php?topic=33280.0

Joe, W3GMS 

[kb3ouk]

If you do use that to monitor your audio, you're porbably going to want to terminate the antenna input with a resistor between the input and ground, I've found that helps with the overload problem. I sometimes use an icom 718 to monitor my audio with, I have a small 50 ohm dummy load that screws right on to the SO-239. It does cut down on the signal some.