Menu

Looking for a specific circuits

Search this Thread

Prev

Previous Post

Next Post

Next

#2

Report Post

Old

June 30th 07, 10:31 PM posted to rec.radio.amateur.homebrew

msg

msg is offline

external usenet poster

First recorded activity by RadioBanter: Apr 2007

Posts: 336

Default

Looking for a specific circuits

wrote:

snip
During the last field day some members of our club ask if it is
possible to connect to the main station two headsets and a speaker at
the same time. Each headset should have his own control of volume. The
volume of the speaker will be control by the vol of the radio.

Pads are commonly used to control volume at the jack in audio distribution
arrangements; I also use headphones which contain a built-in pad for
volume (a slider mounted in one of the earpieces). In the U.S., Radio
Shack used to be a source however I cannot find any at their website.

Use a pad that maintains a nearly constant input impedance to audio across
its adjustment range; the bridged-T pad has both constant input and output
impedance. Make sure the total parallel impedance of the connected pads
matches your audio distribution impedance, (say 600 ohms); use a transformer
to match the audio output impedance of your radios' speaker jack (say 8 ohms).

Consider controlling the radio's speaker with a pad as well so that the line
level remains unaffected by local volume settings.

A site describing pad construction and theory is at:

http://www.uneeda-audio.com/pads/

Regards,

Michael

Reply With Quote

Reply With Quote

Thread Tools	Search this Thread
Show Printable Version	Search this Thread: Advanced Search
Display Modes
Switch to Linear Mode Switch to Hybrid Mode Threaded Mode

Posting Rules
Smilies are On [IMG] code is On HTML code is Off Trackbacks are On Pingbacks are On Refbacks are On

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
battery specific-gravity = AmpHour capacity?	[email protected]	Homebrew	7	January 17th 05 11:38 AM
BC-654-A SCR-284-A circuits ??	Military1944	Boatanchors	0	October 14th 04 07:50 PM
Looking for a specific B&W/Johnson 80 meter plug in coil	[email protected]	Boatanchors	0	April 6th 04 05:11 AM
Radio specific battery charging question	Sanjaya	Shortwave	8	February 6th 04 10:02 PM
Action Circuits	amdx	Homebrew	0	September 19th 03 02:08 PM

All times are GMT +1. The time now is 08:46 PM.

About Us

"It's about Radio"

Contact Us RadioBanter forum home Privacy Statement

Copyright © 2017