Digital Threshold: Automatic versus Manual

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garys

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I had to drive to northern NJ and back the other day. My trip took me through MA, CT, NY (north of NYC), and to Montvale.

I do the trip often enough that I have a SD card set up with systems along the way.

Based on comments in one of the DMR threads I set the digital threshold mode to manual and the value to 5. This has worked well for the DMR systems I follow and the couple of P25 systems in eastern MA. Manual works well on the 700Mhz Commonwealth of MA trunk in the Boston area. Better than it did with the Auto setting, in fact.

The CT State Police system is a Motorola Type II system with P25 voice. I also had this set to manual and 5, but found that it was unreadable in that mode. Previously I had it set to Auto and it always worked pretty well.

On the return trip, I changed the setting to Auto and found much improved reception on the CSP system. I found that the new Waterbury P25 system decodes quite well with the setting to Manual/5

Based on all of this, it seems that DMR and P25 systems work better with manual settings, but the Type II system I listened to works better in Auto.
 

ecarvalho

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....
Based on all of this, it seems that DMR and P25 systems work better with manual settings, but the Type II system I listened to works better in Auto.



Correct. In my experience P25+TDMA system I monitor in my area does much better (not perfect) in manual 7.

I'm not doing anything in DMR until a new firmware is out.

I'm on 1.11.16 as I type this.


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garys

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1.11.17 is available as a beta as of today. However, I made the original adjustments when 1.11.15 was the latest available.

The nearest (to me) system is the 700Mhz system I referenced in my post. After going to Manual/5 decoding improved significantly. There are two other 800 P25 systems, but I'm usually out of range of them.

I've also noticed that neither Sentinel nor the scanners themselves allow a setting below 5. ARC536 does, but I wonder if the scanner actually recognizes that.

Correct. In my experience P25+TDMA system I monitor in my area does much better (not perfect) in manual 7.

I'm not doing anything in DMR until a new firmware is out.

I'm on 1.11.16 as I type this.


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ecarvalho

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1.11.17 is available as a beta as of today. However, I made the original adjustments when 1.11.15 was the latest available.



The nearest (to me) system is the 700Mhz system I referenced in my post. After going to Manual/5 decoding improved significantly. There are two other 800 P25 systems, but I'm usually out of range of them.



I've also noticed that neither Sentinel nor the scanners themselves allow a setting below 5. ARC536 does, but I wonder if the scanner actually recognizes that.



I was laughing at myself because I saw the new 1.11.17 shortly after... but I can't update now as I'm in transit.

DMR near by is just business I have little interest in listening to. It is the ham DMR repeater I care for in DMR for now and sadly they don't make it through my 536 if in One frequency system where I would add TGs and UIDs manually.

Maybe they aren't supposed to be set that way.

The P25 TDMA I listen is on 800Mhz


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darunimal

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Moto Type II try 11-13, also try not using Digital End Code Detection on that type of Sysyem, just End Code with that type system
 
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darunimal

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Phase I & II try 7, with Digital AGC Off 8 may work (but not Default) decently.
 

garys

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I'm pretty happy with the manual settings I have now for the P25 systems and even the conventional frequencies., and auto works well for the CSP system.
 

kruser

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I've always had the best luck with true Manual settings of 6 or 7 for most sites including the new DMR stuff I'm toying with.

My old 996T model likes a level of 5 but that level is almost impossible to get with the hidden P25 menu in the XT series.

I was very glad to see that they brought this feature back with the x36HP models. It just works so much better for me over the auto setting or the hidden menu options in the XT series.

A lot of it seems to be related to my physical location surrounded by cell and tons of paging sites.

If I move away into a rural area, I can often use the Auto setting and my GRE models also work again.

Of course the HP-1 now has officially released firmware that has a radio wide manual P25 setting but that setting does not stick through power cycles. On the HP-1, a level of 6 or 7 also gives me great P25 reception but I do wish they could have given the option to set the level per system and also one that sticks to your setting through power cycles.

Then there is a P25 site on the Starcom system in Illinois that likes a setting of 8 to 10 on the 996T or the x36HPs as well as the HP-1.
That kind of messes me up when I want to monitor my local sites with a level of 6 or 7 and also want to monitor the only Starcom site I can get as I can only set one level in the HP-1. And that level is radio wide and not site specific like the X36HP or T models.
The hidden menu in the XT series can usually be set wide enough that it works fairly well for those sites that like 6 or 7 or the Starcom site that likes 8 to 10 but it's not near as good as the models that let you set a fixed level for each site.

I notice the correct level also helps greatly for sites that are simulcast so a model with a fixed level setting is preferred for simulcast sites in my location.
The models with just an Auto setting are almost worthless on simulcast sites here. They can't never settle down on a good setting so most reception of those sites sounds like encryption sounds like on an older GRE that can't mute encryption!

I wish Uniden could add true manual settings for each site to all models but I don't know if all models firmware would support a true per site manual setting.
I wish the XT series at least had a manual setting similar to what is offered in the HP-1 series. I assume the HP-2 is the same but I never bought one for this very reason.

I do know many where the Auto setting works very well for them but most are rural area users not influenced by tons of cell towers or other nearby digital systems.
The manual setting seems to help those in dense RF environments more than anything.
 

ecarvalho

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What happens when you change to Auto or try 6 or something higher than 7?

That could be a case of severe simulcast distortion also.



https://vimeo.com/179529847

Seems better with manual 5 but still chopped up. I wish LCSO system was easier to decode at least for me...

however ...
https://vimeo.com/179530115

VSP on Auto is clear and very intelligible

fw:1.11.17




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kruser

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https://vimeo.com/179529847

Seems better with manual 5 but still chopped up. I wish LCSO system was easier to decode at least for me...

however ...
https://vimeo.com/179530115

VSP on Auto is clear and very intelligible

fw:1.11.17




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That's a bummer the error rate is all over the place in Manual Mode but Auto mode does seem to work well for the VSP system.

I guess that goes to show you that location can make a big difference.

It's not like you are not getting a poor or low signal level from either system either. Good signal levels on both.

What are you using for an antenna on the Loudoun system?
I wonder if an outdoor 5 or greater element yagi would help narrow your signal down to one tower on that simulcast system if you have not tried one already.

I've had some really good luck eliminating simulcast using a corner reflector antenna. The kind that has solid panel reflector panels and not the open wire mesh type reflectors. They seem to really help knock down the signal from sites outside the antennas beamwidth but they also come with a higher wind load area so must be mounted securely.
They can have as much gain as a 12 element yagi as well.

I'll usually mount those or yagi's on a mast with a rotor but as luck has it, the signals of interest usually come from opposite directions so I end up using a yagi as it still lets in plenty of signal from the sides or back on strong sites.
 

ecarvalho

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I'm not allowed external antennas and I don't have an attic. The picture is from my desktop discone.

Is there a directional for desktop use? I could build one I suspect


3bd3ac4ba568aebeec92e6bad00a1ea3.jpg
 
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ecarvalho

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Here is an indoors beam (Yagi) for 700/800 Mhz band... I would rather just build one up for testing purposes.
Indoor 700/800 MHz Yagi Directional Antenna with Desktop Stand | Scanner Master

Some reviews for this Yagi:

Best Antenna Ever Owned

January 21, 2015
Reviewer: Steve B from Littleton, CO

I love this thing! It is great at pulling in distant 800MHz sites and also works well at pulling in a 700MHz simulcast cluster on my BCD536HP. The PVC pipe setup works extremely well (I actually use a C-Clamp to clip it to the corner of a wall in whatever room I'm in. Highly recommend!




I beat Simulcast! :0)

March 31, 2015
Reviewer: Johnnydollar2 from Chicago, IL

A VERY good Antenna. Don't be scared off by Freq-range limits. You still get most of what you normally do. 406.000-470.000, 160-172 Federal, even Airband came in good. Local 155.000 gained signal/volume, very happy with that. Best is I hear both sides of phase II TDMA signals loud and clear as I had simulcast issues. Before buying the antenna, some signals clipped and went silent on the P25 800mhz trunked system I monitor. NOW I hear all. Even worked as a mobile antenna on a hard to get local 700mhz trunked system just sitting next to my car door. I can only imagine how great it is on the roof or in an attic. Mine is just pointing out a 2nd story window. Enjoying my WS1080 a lot now. Thanks :0)
 

ecarvalho

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2586e0ace77a7bbd21f592eb61528940.jpg


Analysis of LCSO (using my desktop discone)
Note: Moving it around didn't help. I will try building a simple yagi directional and experiment on this system to see if I improve my reception.

This is the simulcast site tower location:
http://www.radioreference.com/apps/db/?fccCallsign=WPRS263
As it appears, I'm in the middle of transmitters location 1, 3 and 4 so I guess folks are right, I must be suffering of a simulcast issue.
 
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kruser

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That's a neat looking little discone!

I've tried indoor yagi's that were intended for outdoor use.
Some have luck but mine made things worse due to reflections from metal cabinets and the like.

You probably could try building a simple yagi and see what it does.
Something simple and cheap. It may be worth a shot.

Yagi's are actually pretty simple and for testing purposes, it does not need to be pretty!

I was in the same boat as you living in the apartment I still live in.
One day came where I had a valid reason to have an antenna on the roof. I live on the top floor. I was surprised when the apartment manager gave me a key for the roof hatch and written permission to install what I needed.
They still allow it to this day and I now have multiple antennas on the rooftop. I do try and keep them to a limit though as I don't want to push my luck.
I first needed to get a signal from a 902 to 928 lightning detection transmitter located at work about 1.2 miles line of site.
I bought a yagi for that band and it worked fantastic.
Since, I've put up single or multiband antennas of the omni or directional type as well as a loop and several long wires for HF stuff.
I keep the wiring nice and tidy and they are happy. I do consider myself very lucky they allowed it but the main reason for it was a true valid reason and still is to this day. I've had various antennas above my apartment for over 20 years now.
I do tend to remove one though if I'm installing something new to keep the count down.
Luckily they are not that visible from the street so that helps as others here do not really notice them.
Only one is used for transmitting back into my business repeaters at work but I only need a watt or two so no interference complaints.

I'd experiment with building a simple yagi if you have the time and knowledge to try it. If you have a window facing one of the towers giving you problems, that would be the window to aim the yagi through.

I once had a 20 something element yagi for 900 MHz. made for amateur radio that I bought up at Dayton a long time ago. I had it hanging in my bedroom aiming out the window at the site I was after. I had multiple hooks in the ceiling so I could change the aim a few degrees.
It did actually work but not near as well as I really wanted.
The wife did not care for it though!
I changed the reflectors with a pair from a TV antenna and that also helped. It was shortly after that when I was allowed to install an antenna on the roof. I never did install that huge yagi on the roof as it was almost 10 feet long with all the elements it had!
I ended up using a 12 element Maxrad yagi that was made for 800 MHz but it also worked well for the low power 900 MHz signal from the 900 MHz freeband (ISM Band) radio signal I needed. With luck, the aim to work was also inline with the aim I needed for the cities new 800 MHz trunked system.

Some people use wood broomstick for a homemade yagi and some use PVC pipe. Either should work for a crude antenna test.

My apartment itself is covered in Stucco which is applied to a wire mesh. It's almost like I live in a Faraday cage so indoor antennas did not work unless I had a window to aim through.
I've only used indoor antennas for really strong signals the past 20 years or so.
One thing about the Stucco walls is that it also helps keep the neighbors EMI/RFI noise out!
You may get by with a tiny 3 element yagi with the signal strength you are showing.
You just need to try and null out all towers except the strongest one it looks like.

I'm not familiar with the antenna in your link from ScannerMaster.
It seems pricey though so I'd try and build something before investing that much money in something that may not work.

An UHF yagi style TV antenna may also work and you can usually find something cheap at places like best buy or even some of the big box hardware stores.
Try and find a UHF only model usually sold as an HDTV antenna that is not amplified. The amplifiers in those usually add more noise than any gain they offer and if you can find one for UHF only, it should keep the size down. If it does not work, you should be able to return it.
That would be easier than building one!
The UHF TV band starts just above the 800 MHz public safety band but should still work for the 800 MHz public safety band.
You will have a slight mismatch in impedance from 75 ohm at the antenna to the 50 ohms a scanner is looking for but for reception only, that should not matter. You can even use quad shield 75 ohm coax as it has very low loss at 800 MHz and is small diameter compared to something like LMR-400. Then you only need one adapter at the radio end to convert from an F connector back to a BNC.
If you have a camera tripod, you can mount it on top of that and see what happens.
If it works well, then build something that fits better indoors.
Wilson also makes some small non amplified cell phone signal booster antennas that are very small and contain a tiny yagi inside the weatherproof housing. They sell one that covers down to the 700 MHz band on up. The whole thing is only about a foot long and has an N connector output for 50 ohms. They don't really offer much gain but the directional properties are very good. Here's a link for one that looks like the one I have but mine does not offer such a high freq range. Hopefully the link will open.

https://www.wilsonamplifiers.com/wi...0ohm-314411/?gclid=CI_QuomAz84CFZU1aQodUbUP_Q

They are small and don't really offer any gain but do have decent directional properties and do help null out signals off to the side that may be causing simulcast problems.
You can find them cheaper and don't let the claimed gain fool you. They really don't offer that gain but I don't think you really need any gain, you just need to null out the signals from the other towers on your simulcast system.
 

pro92b

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I would first aim the antenna due west, slightly to the south of that nearest tower. Maybe try with the attenuator on as well. How did you get the radio into the Analysis of LCSO mode and what do the three bar graphs mean?
 
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darunimal

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On the desktop scanner I'd point the antenna due north and let the null spot at the top do the nulling of the three Northern towers and maybe even put Attenuation on or Try a Squelch at 7-9 maybe even 11.

PG loves 6-7 on manual, Fairfax didn't do bad on 7 either. VSP I pickup great on a couple GRE's and an 396XT on Auto.

The P2 series has the hidden menu making it a b.... to use but doesn't always stay correctly, it "Autos" a slight bit while on Manual and it depends on how you enter the main Menu and unto how you scroll to Settings and you number, buggy at best.
 

ecarvalho

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That's a neat looking little discone!
(...)
https://www.wilsonamplifiers.com/wi...0ohm-314411/?gclid=CI_QuomAz84CFZU1aQodUbUP_Q

They are small and don't really offer any gain but do have decent directional properties and do help null out signals off to the side that may be causing simulcast problems.
You can find them cheaper and don't let the claimed gain fool you. They really don't offer that gain but I don't think you really need any gain, you just need to null out the signals from the other towers on your simulcast system.

I will first build a simple test yagi and see if it helps. I will save the URL and later get that if my tests are positive with a directional. Thanks. This discone is fantastic but omnidirectional and for LCSO is not good.

Thanks for the answer reply!
 
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