N9NJS, Might look at some of the Mot and GE voters. They are old, but had some very good circuits and operational modes. I've used their input circuits to clean up digital and other modes before whatever I was driving. The GE used a tone to indicate no rcv input as a means of locking out a rcvr so one did not vote on it, tone present rcvr had no input. Simple, but good.
I'm using a driver circuit from a Mot voter to build a D-Star interface from a receiver. Cleans up things. GE had some real good S/N voters. This might give some good ideas. I built a voter once. Did not go far with it. I liked the auto leveling I built in. Voters are usually critical on level. Was using digital pots in an auto alignment mode to set the levels so all receivers would have same level. Would go to TX site and insert rig with tone on input freq and put voter in auto-align mode and it would adjust levels. Of course still did not correct for response differences. 73, ron, n9ee/r >From: Cort Buffington <[EMAIL PROTECTED]> >Date: 2008/06/18 Wed PM 01:41:48 EDT >To: Repeater-Builder@yahoogroups.com >Subject: Re: [Repeater-Builder] Voter Audio > >Folks, >I have been working on voter design lately. I'm a ham, I don't make my money >working on radio, so I can both do this stuff slowly for fun. I have >constructed the S/N circuits in the LDG, and the original QST article the LDG >S/N section was based on... And about 1/2 dozen variants of my own adding to >and changing things in the design. The LDG circuit works very well. The >problem I found was a large disparity in response between linked radios and >the local receiver. Every radio in the system throughout my tests has been >standard narrowband (+/-5kHz). >This work has not been to make a better voter than LDG or Doug Hall, but just >because I want to. I am currently building a valley type S/N detector to >measure the performance difference with that stye. The one thing LDG really >has going for them is that the S/N circuit connects to an ADC and a >microprocessor. The S/N detector is already clean, and connecting my own >designs to an ADC and microprocessor, I can see where they likely make great >improvements with software on top of the hardware. >FWIW73 DE N0MJS > > > >On Jun 18, 2008, at 11:17 AM, skipp025 wrote: > >> They type of audio used from the receivers can be just about >> any type as long as all of the receivers use the same audio. > >Not really... depends on the specific voter circuit. > >> Audio types that are acceptable are line level and speaker >> audio. > >Any composite audio within the the level-range of the voter >circuit (varies with the specific voter circuit) and containing >the proper spectral components required by the voter circuit. > >> Also, it does not matter if the audio is de-emphasized or >> not as long as all of the receivers are the same."<br><br>The audio doesn't >> have to be the same... but one would like to<span >> class="Apple-converted-space"> >say for most cases it's probably better. The de-emph yes or no >requirement is again dependent on the specific voter circuit >design and how it performs. > >> It goes on to mention that audio response is the biggest >> challenge, try and get the audio response the same on all >> channels for best performance. > >As a general rule of thumb probably so... but if you understand >the voter circuit... you can simply equalize the inputs where >required. > >cheers, >skipp > > > --Cort BuffingtonH: +1-785-838-3034M: +1-785-865-7206 > > > > > Ron Wright, N9EE 727-376-6575 MICRO COMPUTER CONCEPTS Owner 146.64 repeater Tampa Bay, FL No tone, all are welcome.
