SDR Based Voter System (experiment)

[RFI-EMI-GUY]

The reason has to do with how it's built. RF Technology has a single site trunking card (for multi-site you interface with an Atlas controller). It's setup similarly to the way the older Intellirepeaters were setup and there is no authentication. You can go in and add the simulcast option to those repeaters and create a simulcast system (de-centralized). You can't expand it to multi-site wide area without hooking it up to the Atlas controllers. This, single site (controller) simulcast (option).


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I know, it is just confusing terminology that the industry has failed to correct. I read folks commenting all the time here on RR that they want to select a different "Site" with their scanner to avoid Simulcast interference.

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[kc1efx]

JPS is coming out with the SNV IP. Should be out soon. Add IP voting to your SNV without homemade gimmicks.

https://jps.sugarmapleinteractive.c...17/08/JPS_DataSheet_4Page_SNV12IPBack_web.pdf

Lifesaver...

 

[RFI-EMI-GUY]

JPS is coming out with the SNV IP. Should be out soon. Add IP voting to your SNV without homemade gimmicks.

https://jps.sugarmapleinteractive.c...17/08/JPS_DataSheet_4Page_SNV12IPBack_web.pdf

Excellent addition to their product line. Raytheon was stupid for cutting them loose.

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[FireMarshalRob]

So the system I'd actually recommend for doing this is manufactured by a company called RF Technology. Uses software defined repeaters which can be setup for P25 trunking, conventional voting, conventional simulcast or even trunking simulcast (as long as it is single site). Many know the equipment as the Eclipse 2 repeater has been relabled and offered by Icom for several years now. The Eclipse 3 (which isn't into full production yet) is fuly softwared defined (the TX/RX unit has a lockable VCO range from VHF-Lo through 800 MHz) and is supposedly going to be relabled by EFJ at some point to fill the gap created by the expiration of their contract with Simoco relabling the SB2025NT (which means it'll be available to Kenwood dealers). Oh yes, DMR operation is a software release being developed for both Eclispe 2 and 3.

Voting/simulcast operation is based off of ping latency and BER/SNR depneding on whether or not we are talking about digital or analog. Once you get to the IP side of things, it's all routing (leased or owned PTP circuts are best for this though). All analog audio is carried using SIP standards (and there is direct SIP PBX integration available).

Not to be a douche, the RFT gear is cheap junk (for that matter so is icom). I would never even think about placing any of that gear into any type of public safety service. No intelligence whatsoever, nothing about it has any type of duty cycle, and the power supply is an ict $75 special with tabs pop riveted on and stuffed into it. No to mention the fact that the front ends are crappy and get killed on busy sites. For ham, business use I guess you could make it work.

They ripped off the design of the Tait gear (which is real deal equipment) and really cheaped out.

 

[Project25_MASTR]

Not to be a douche, the RFT gear is cheap junk (for that matter so is icom). I would never even think about placing any of that gear into any type of public safety service. No intelligence whatsoever, nothing about it has any type of duty cycle, and the power supply is an ict $75 special with tabs pop riveted on and stuffed into it. No to mention the fact that the front ends are crappy and get killed on busy sites. For ham, business use I guess you could make it work.

They ripped off the design of the Tait gear (which is real deal equipment) and really cheaped out.

I've actually spot checked a handful of them at the Lufkin production facility. Everyone I've tested met or exceeded the listed specs (100 dB adjacent channel rejection, 12 dB SINAD @ -118 dBm, even had one TX/RX module hit 5% BER @ -126 dBm). I also know where a few Eclispe 2's are running at 95% duty (in an area affected by Hurricane Harvey actually) for a state agency...4 years and zero issues.

Now, I have heard some bad things about the first generation Eclipse and first revision of the Eclipse 2...haven't been able to find anything bad about current revision (either from few hundred purchased by TSA or the 1200 purchased by USCG). I have also heard some bad things about the paging transmitters (which here lately RFT has been pushing the Eclipse 2 for paging).

 

[lmrtek]

I've never needed a voting system on any repeater I've ever installed so unless you are running massive amounts of transmit power, you should be able to get your repeater to hear just as well as its transmits with little effort

The antenna may be the wrong type for the terrain or you may have a mistuned duplexer, repeater, or you have desense

Out of 1O local ham repeaters, only ONE has zero desense so I suspect you too are encountering desense

I've installed many 100 watt vhf repeaters and never needed remote receivers to produce excellent hand held coverage

And I've seen voting systems installed by both professionals and amateurs over the years and I've yet to hear one that actually works reliably and they wind up being a constant source of problems

 

[12dbsinad]

I've never needed a voting system on any repeater I've ever installed so unless you are running massive amounts of transmit power, you should be able to get your repeater to hear just as well as its transmits with little effort

I've installed many 100 watt vhf repeaters and never needed remote receivers to produce excellent hand held coverage

30 years ago I'd agree with you 100 percent. In today's world, the VHF band is getting pretty nasty unless you are out in the country. The noise floor at some sites is unreal, combine that with co-channel crap, POE units on the sites radiating EMI, cheap LED tower lights, etc all play are roll. The newest saga that's taking off by storm are VHF BDA amplifiers being placed in buildings. Not only does it amplify your handheld to the outdoors, it also amplifies all the other garbage that gets produced in the building. Add a lot of those up and you find yourself with a mess. Don't ask me how I know.

 

[quad_track]

If you want something full SDR, you don't need multiple equipment pieces. Many SDRs offer diversity with 2-4 receivers. Check out the NI site for some of them.