Warning: Creating default object from empty value in /homepages/11/d132647312/htdocs/Amfone/mkportal/include/SMF/smf_out.php on line 47

The AM Forum
June 02, 2020, 09:14:20 PM *
Welcome, Guest. Please login or register.

Login with username, password and session length
   Home   Help Calendar Links Staff List Gallery Login Register  
Pages: [1]   Go Down
Author Topic: Optimod  (Read 804 times)
0 Members and 1 Guest are viewing this topic.

Offline Offline

Posts: 3

« on: March 02, 2019, 11:39:18 AM »

Could someone tell me the difference in the  Optimod FM vs AM.. I am wondering if the FM model could be used on AM
Offline Offline

Posts: 123

« Reply #1 on: March 02, 2019, 04:00:27 PM »

Short version:  FM includes the stereo encoder, has a pre-emphasis network. AM does not. Unless it's rather old, AM probably has NRSC filtering. FM does not.  Multiband compression bands are different due to the bandwidth of broadcast FM vs AM (no need to compress/limit 6-15kHz on an AM if you're just going to filter it off).

Can you use it? Sure. You need to disable the 75uS preemphasis, turn off the stereo, and add your own LPF/NRSC type filter on the output.


Ed, K8DI, warming the air with RF, and working on lighting the shack with thoriated tungsten and mercury vapor...
Offline Offline

Posts: 8220

"Let's go sailing, Tommy!" - Yaz

« Reply #2 on: March 02, 2019, 06:06:20 PM »

"Ed, K8DI (fmr. KB8TWH) "

Boy, did you get rid of a giant gorilla on your back...  congrats, Ed  -    Grin

Tom, K1JJ

Use an "AM Courtesy Filter" to limit transmit audio bandwidth  +-4.5 KHz, +-6.0 KHz or +-8.0 KHz when needed. 

There's nothing like an old dog... or a puppy, or a dog in his prime!  Help a good dog - give him a "Forever Home!"
Pages: [1]   Go Up
Jump to:  

AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
 AMfone 2001-2015
Powered by SMF 1.1.21 | SMF © 2015, Simple Machines
Page created in 0.044 seconds with 18 queries.