Suggestions for scanner with high intermod rejection

[videobruce]

My number one problem/issue is intermod. I'm looking for a scanner to use under these conditions;

1. High intermod rejection on VHF high band,
2. Mobile (not a handheld),
3. Separate control head ok (if such an animal exists),
4. I have NO interest in Fire, EMS and suburban Police or low band traffic,
5. Knobs you can access without tweezers and a display you can see without a magnifying glass,
6. Banks of only 20-40 channels each,
7. Interested in receiving: Railroads, City, State and Federal services, Marine, some business, some Military aircraft and trunking ability.

I haven't kepted up with all these new 'digital' scanners especially since my area really doesn't have any of those new APCO (or whatever they are called) services.

Suggestions please.

[WayneH]

High intermod rejection and trunking don't go together unless you're using a commercial two-way radio. Many of the high-end receivers such as what ICOM makes are vast improvements over the Uniden and GRE/RadioShack scanners. The problem is they don't natively support trunking.

I would only suggest going the Motorola route once you understand many things: costs of the hardware and software, the difficulties of monitoring trunked systems, and learning how to properly program equipment. It's equipment you just don't go out and buy without any prior knowledge.

[zz0468]

I have to agree with Wayne, you have some mutually exclusive requirements.

You specifically mention VHF intermod rejection. Is that the only band of interest? Do you actually have an intermod problem, or are you just afraid you'll have one? an you prioritize these requirements? Can you live without any of them? Can you fulfill your requirements with multiple radios?

[N8IAA]

Originally Posted by videobruce

My number one problem/issue is intermod. I'm looking for a scanner to use under these conditions;

1. High intermod rejection on VHF high band,
2. Mobile (not a handheld),
3. Separate control head ok (if such an animal exists),
4. I have NO interest in Fire, EMS and suburban Police or low band traffic,
5. Knobs you can access without tweezers and a display you can see without a magnifying glass,
6. Banks of only 20-40 channels each,
7. Interested in receiving: Railroads, City, State and Federal services, Marine, some business, some Military aircraft and trunking ability.

I haven't kepted up with all these new 'digital' scanners especially since my area really doesn't have any of those new APCO (or whatever they are called) services.

Suggestions please.

1. Not going to find to many scanners with intermod rejection on VHF.
2. See (3). Also, GRE PSR-600 and the RS version: Pro-197 are other mobiles that will receive what you are looking to monitor.
3. Uniden makes a remote control head for the BC15, BC396, BC996, BC396XT, BC996XT.
5. Most new analog and digital scanners operate well without tweezers Most have decent displays that are backlit.
6. Most new scanners don't have banks anymore. They use either Dynamic Memory Assignment, or, Object memory.
7. Railroads are still analog, most city, state, and federal agencies are going digital trunked, or, digital conventional. Marine is still analog. Businesses are mostly analog. Military aircraft is analog UHF AM mode.

Larry

[videobruce]

Do you actually have an intermod problem

Yes. Also on UHF, but not as much. Pagers mostly. (What else is new.)

Many of the high-end receivers such as what ICOM makes are vast improvements over the Uniden and GRE/RadioShack scanners.

But, don't those fail as scanners? Great receivers, poor scanners.

Can you fulfill your requirements with multiple radios?

Not really. There will be another radio for xmit along with this receiver and that's pushing it.

most city, state, and federal agencies are going digital trunked, or, digital conventional.

As in encripted (secure), or just digital?

[vabiro]

Originally Posted by videobruce

As in encripted (secure), or just digital?

I noticed you're in Buffalo NY. Isn't NY setting up a new state-wide digital network that will be used by the City and State users?

Victor

[videobruce]

I don't know. I don't follow all of those 'proposals'. The country has been talking about it for some time. Considering the 'state' of the state, I would doubt it.

More waste of $$. Problem is, these communication manufactures are trying to re-invent the wheel when it isn't necessary. New and improved, isn't always.

[N8IAA]

Originally Posted by videobruce

.As in encripted (secure), or just digital?

Some are encrypted, some aren't. It depends on the type of conventional P-25 that is used. I find that paying over $500 for a communications receiver that is even more prone to intermod is a bit over board. All though, the Icom R-1500 would do most everything but trunking. It is the same price as the handheld R-20. Wide band receivers, (even the newer scanners) do get hit by high powered transmissions. It seems the state of NY isn't going to go trunked anytime soon by what is being posted in the NY forum here on RR. For your immediate area, VHF, UHF seem the way to go. What I saw for the Buffalo metro area can be serviced by a RS Pro-163, or, Uniden BC-15. Getting a digital would be neccessary if you are planning on monitoring Canada.
HTH,
Larry

[N8IAA]

Originally Posted by videobruce

More waste of $$. Problem is, these communication manufactures are trying to re-invent the wheel when it isn't necessary. New and improved, isn't always.

Not always the case. Here in Metro Atlanta, the City of Atlanta is broke. They have closed down fire stations, furloughed PD and FD, but have put in place a P-25 digital public safety system. De Kalb, who had one of the oldest trunked systems in existence, just put on the air a P-25 system. The CEO of De Kalb just went on TV yesterday to tell everyone in that county the increase in real estate taxes was going to be over $200 more a year. Just look elsewhere in the country and you will see the same. It has been a fat hog feeding frenzy (communications companies) with all the fed $$$ being handed out.
JMTCW,
Larry

[WayneH]

Originally Posted by videobruce

Yes. Also on UHF, but not as much. Pagers mostly. (What else is new.)

You might try filters to handle pager intermod. The Wiki covers it and lists some companies.

But, don't those fail as scanners? Great receivers, poor scanners.

Well, it's hard to answer without knowing what one truly expects out of a scanner; my answer: yes. The scanning speed is slower. Tone search is slower/a generation behind. Basically, you lack a lot of the frills scanners come with. They're definitely not marketed as scanners.

Unfortunately you can't have one communications receiving device that will do it all. It's not made. Even Motorola radios scan slowly. I run my ICOM PCR2500 alongside a GRE500. Where one fails, the other takes over.

[videobruce]

I find that paying over $500 for a communications receiver that is even more prone to intermod is a bit over board.

Explain.

You might try filters to handle pager intermod.

I thought about that, but those filters are too broad banded. I do need 155 MHz coverage.

Unfortunately you can't have one communications receiving device that will do it all. It's not made. Even Motorola radios scan slowly. I run my ICOM PCR2500 alongside a GRE500. Where one fails, the other takes over.

Apparently this hasn't changed in the past 15 years or so?

[N8IAA]

Originally Posted by N8IAA

I find that paying over $500 for a communications receiver that is even more prone to intermod is a bit over board.

My personal observation. I used an Alinco DJ-X10 for over twenty years in combination of public service/milair/conventional frequencies. As trunking became the way to monitor public service, the Alinco got used less and less. It got hit by everybit of intermod near me. I have always had some kind of tower nearby that blanketed many frequencies that were monitored. Filters were mentioned, but as you said, cuts the area out you wish to hear. Try notch filters. You can cut out specific frequencies with those. Again, just my observation.
Larry

[videobruce]

Try notch filters. You can cut out specific frequencies with those.

As I stated. they are too wideband unless you spend really big bucks for a narrow band version.

[SkipSanders]

The problem you face is that to be effective as a scanner, the front end has to be open to the whole band. That means poor rejection of off frequency but high power transmissions like pagers.

Commercial gear avoids this by having front ends that auto tune to the specific channel, or at least, a narrow range, rather than being wideband all the time. This, naturally, costs. That's why you don't see it in scanners, though they do sometimes have 'bandpass' front end tuning, so that a VHF channel sets the front end to a VHF (wide) filter, etc.

Getting good intermod rejection is a matter of cost. Consumer grade electronics don't have it. Commercial grade does.

[kd7rto]

My advice is to go old school. Since ctcss and trunk tracking have become standard features, manufacturers apparently feel that spurious signal rejection is no longer as important. My BC796D get's clobbered when I put it on an outdoor antenna, but my Optoelectronics Optocom and my Pro-2006 both work just fine.

For trunking, keep in mind the fact that there is software available which will enable your PC to control your receiver, in order to follow trunked systems on receivers with no built in trunktracking capability.

Using my Pro-2006 as the data receiver, the Optocom as the voice receiver, and running M Trunker for Motorola or E Trunker for EDACS, is still IMO the best system available for live monitoring at home. Mobile monitoring and digital audio logging are the only reasons I’ve kept the BC796D.

[videobruce]

SkipSanders; I fully realize all of that. I should re-word the request to include "within reason". I know NO scanner will come close to a commecial receiver. I'm just looking for something that is better that most.

I have a Pro-2004 and a Regency HX-1000 (which I will not sell inspite of it's limited features). That 25 year old Regency can't be touched. It's not commecial quality, but it is far above any scanner I have had my hands on.

Problem is I haven't had any experiance with anything newer that the 2004/2006.

[gewecke]

A good way to solve the intermod issue,would be to pick a triple conversion receiver.
Check the specifications while shopping. Most that are intermod-prone are only dual conversion.
N9ZAS.

[Mike_G_D]

Originally Posted by gewecke

A good way to solve the intermod issue,would be to pick a triple conversion receiver.
Check the specifications while shopping. Most that are intermod-prone are only dual conversion.
N9ZAS.

That's actually kind of a fallacy. If all other things are truly equal then, theoretically, a well designed triple conversion receiver should have some advantages over a double conversion receiver in terms of some types of interference rejection (primarily image rejection). However, simply put, a well designed double conversion receiver can out perform a triple conversion receiver of lesser design quality.

In general, the number of conversion steps in a receiver does not always provide the best indicator of interference rejection performance, especially in consumer quality receivers.

The GRE PSR500/600 is a triple conversion receiver and is well known to experience significant overloading and intermodulation issues. So, if I were you I would treat the conversion steps in consumer grade receiver gear with a bit of the old "grain of salt" rule. That being said, pretty much all (I think actually ALL) modern digital capable trunking scanners out there now are triple conversion so the point is kind of moot.

Videobruce - you might try looking into the choices at WiNRADiO Communications - The future of radio. if you are not needing to go mobile or portable. The 315 series should offer very good performance plus P25 decode but they don't yet have a trunking package for them. The lower cost mainstream 305 series still look like they should offer better interference rejection than your typical consumer scanner and they do offer a trunking package as well as a P25 decoder for those units. The trunking package (control software, I believe) does not yet handle 9600 baud P25 systems but, according to the description, this is in the works and will be added at a later date. These may be pricey options but they still may be the closest overall solution for you.

-Mike