Mass Confusion

[owl9704a]

Ok people I need some clarification here. I have been playing with listening to public service radio since 59. My first radio was a Hallicrafters Civic Patrol, 30 mto 50 mz model. With who remembers what for an antenna. And since then i have probably had more scanners than I could put in a truck. Now I have 4 SDS 200's, an SDS 100 and a 536. all with every option available. I have recently decided to upgrade my antenna from the old Tram to a Diamond and a DPD unity I think, it has not arrived yet. ANd I have again changed all of my coaxes. I am now using LMR400 with type N connectors since they say the pl259 is not goods for higher frequencies. Since when? And i have been looking for a good lightning arrestor but no matter where I look there is not one available that covers the entire scanner range. I can find them for VHF 150 band and UHF 450 and some that cover 700 to 900 and some that cover from 900 to 2000. But I have yet to find one from any major supplier that covers everything these scanners are capable of. And just for the fun of it who decided that we needed to use LMR400 for a receiver antenna as opposed to th4e good old RG8? And what is with this N connector stuff now? Now I have several Harris that use that connector exclusively but they are 100-watt P25 units. I have just been getting confused with all of this new stuff and it is really making this one expensive hobby.
Ok so does anyone know where to get a full coverage lightning arrestor? And does anyone know where all of the information I have read in posts on so many forums comes from about this cable and connector stuff? We have used PL259 connectors for decades and they always worked. And we used RG8 and 58 for years and it worked. Did this stuff come from some engineer with a computer or did it come from someone that actually took several units and hooked them to identical antennas and used different cables? I guess when you get older it is just hard to figure out some of these new ideas that are supposed to be better. If anyone has some help for me I would greatly appreciate it. This is the only forum that really deals with these units.
Thanks for your time
owl9704
Bob

 

[nd5y]

Ok so does anyone know where to get a full coverage lightning arrestor?

If these companies don't make it then it probably doesn't exist.

https://www.polyphaser.com

Solutions for Lightning Protection, Bonding, and Grounding | Harger Lightning and Grounding

Since 1960, Harger has been providing solutions to the lightning protection and grounding industries. We have experience in all facets of these markets including engineering, systems design, product manufacturing and installation.]

www.harger.com

Alpha Delta Communications

 

[sallen07]

And i have been looking for a good lightning arrestor but no matter where I look there is not one available that covers the entire scanner range. I can find them for VHF 150 band and UHF 450 and some that cover 700 to 900 and some that cover from 900 to 2000. But I have yet to find one from any major supplier that covers everything these scanners are capable of.

DIAMOND SP3000P

Lightning Arrestor DC - 3000 MHz 400 Watts PEP N Connectors

www.hamradio.com

That's one option (the one that I am using in front of my multicoupler). HRO has several others that will meet your needs.

And just for the fun of it who decided that we needed to use LMR400 for a receiver antenna as opposed to th4e good old RG8?

Coax Loss Calculator | KV5R.COM

The higher the frequencies, the higher the line loss.

With 50 feet of RG-8, you are losing 25% of the signal at 150 MHz. LMR-400 17%

Same 50 feet of coax at 800 MHz? 54% loss with RG-8 versus 36% with LMR-400. Big difference.

Will RG-8 *work*? Sure. But LMR-400 will work better.

 

[mmckenna]

Ok so does anyone know where to get a full coverage lightning arrestor?

If you are not running power up the coaxial cable to a preamplifier, this one will do what you want:

https://www.polyphaser.com/type-n-surge-protector-1.2ghz-gas-discharge-tube-098-1013g-a

If you ARE running power up the coax to a preamp, then you need one of these:

https://www.polyphaser.com/type-n-surge-protector-3ghz-gas-discharge-tube-103-0324a-a

And does anyone know where all of the information I have read in posts on so many forums comes from about this cable and connector stuff? We have used PL259 connectors for decades and they always worked. And we used RG8 and 58 for years and it worked.

UHF connectors were originally designed as a shielded banana plug connector. They were quite popular for a long time, and still work fine for lower frequencies and most hobby/ham use. Nothing wrong with them if you are listening to scanners, CB, ham radio, etc.
The problem with them is that they do not provide a perfect 50Ω impedance, and their performance starts to show its weaknesses as you get up into the UHF and higher frequencies.
Again, none of that is a problem for scanner/ham/hobby use. The scanner/scanner antenna won't give you a perfect 50Ω match, so a bump in the connector isn't going to be a big deal. They do start to show more loss as you go higher in frequency, which is a problem for those running higher spec stuff, transmitting, etc.

The benefit to the "N" connector is that they give a near perfect 50Ω impedance. They have less loss as you go up in frequency. They are also better at making a seal for outdoor use (you still need to waterproof the connector when it's mated).

As for coaxial cable….
As your cable gets longer, the losses go up.
As your frequencies get higher, the losses go up.
Back in the days of CB and VHF low band, that wasn't a big deal. RG-58 for short runs and RG-8 for longer runs was 'good enough'.
As radio systems started moving into higher frequencies (700MHz, 800MHz, 900MHz), the feed line losses became a bigger issue for long cable runs.

But, again, for hobby use, if you can hear what you want to hear, then what you have is likely good enough.
Unfortunately, LMR-400 has reached this mythical status as the be-all/end-all of coax cable. It isn't. It's decent stuff, but there are better cables out there. It's usually a pretty good step up for hobby use, it's fairly easy to work with, and the user gets some bragging rights. All OK, but there's are better cables out there….

 

[mr10pt]

Just my opinion (but I'm a carpet installer not an ET or EET), you stated scanner not transceiver. I run RG6 for receive only. I guess it would depend on your system(s) and range you're trying to hear. I installed LMR400 with an N connector for my SDS200. Zero change in reception for the 5 county area (simulcast P25 P2) systems. Only one analog system 25ish miles south. Strong reception with RG6 and a Tram Discone. Now the RG6 resides in an outbuilding and the sausage cable, LMR400, is in the house. Very stiff, bulky and expensive for no reason. I'd put it on the 2 meter/440 antenna it were easy to access but the Mini 8 works very well for local repeaters.

 

[owl9704a]

If these companies don't make it then it probably doesn't exist.

https://www.polyphaser.com

Solutions for Lightning Protection, Bonding, and Grounding | Harger Lightning and Grounding

Since 1960, Harger has been providing solutions to the lightning protection and grounding industries. We have experience in all facets of these markets including engineering, systems design, product manufacturing and installation.]

www.harger.com

Alpha Delta Communications

OK, I went to the Polyphaser site and they do list one that should do what I need. My issue was if you looked at the label on the unit it said something different. But I have ordered two of these from them.
Thanks much

 

[owl9704a]

DIAMOND SP3000P

Lightning Arrestor DC - 3000 MHz 400 Watts PEP N Connectors

www.hamradio.com

That's one option (the one that I am using in front of my multicoupler). HRO has several others that will meet your needs.

Coax Loss Calculator | KV5R.COM

The higher the frequencies, the higher the line loss.

With 50 feet of RG-8, you are losing 25% of the signal at 150 MHz. LMR-400 17%

Same 50 feet of coax at 800 MHz? 54% loss with RG-8 versus 36% with LMR-400. Big difference.

Will RG-8 *work*? Sure. But LMR-400 will work better.

O that means someone has actually proven this other than a salesman or engineer being paid by a company to make their product look better. That does make me feel better my runs are almost 150 feet each when going up that 70-foot pole it takes some cable. ANd i guess it will maske a difference in the long run. I sure hope so with what they charge for LMR400 these days.
Thanks Bob

 

[owl9704a]

If you are not running power up the coaxial cable to a preamplifier, this one will do what you want:

https://www.polyphaser.com/type-n-surge-protector-1.2ghz-gas-discharge-tube-098-1013g-a

If you ARE running power up the coax to a preamp, then you need one of these:

https://www.polyphaser.com/type-n-surge-protector-3ghz-gas-discharge-tube-103-0324a-a

UHF connectors were originally designed as a shielded banana plug connector. They were quite popular for a long time, and still work fine for lower frequencies and most hobby/ham use. Nothing wrong with them if you are listening to scanners, CB, ham radio, etc.
The problem with them is that they do not provide a perfect 50Ω impedance, and their performance starts to show its weaknesses as you get up into the UHF and higher frequencies.
Again, none of that is a problem for scanner/ham/hobby use. The scanner/scanner antenna won't give you a perfect 50Ω match, so a bump in the connector isn't going to be a big deal. They do start to show more loss as you go higher in frequency, which is a problem for those running higher spec stuff, transmitting, etc.

The benefit to the "N" connector is that they give a near perfect 50Ω impedance. They have less loss as you go up in frequency. They are also better at making a seal for outdoor use (you still need to waterproof the connector when it's mated).

As for coaxial cable….
As your cable gets longer, the losses go up.
As your frequencies get higher, the losses go up.
Back in the days of CB and VHF low band, that wasn't a big deal. RG-58 for short runs and RG-8 for longer runs was 'good enough'.
As radio systems started moving into higher frequencies (700MHz, 800MHz, 900MHz), the feed line losses became a bigger issue for long cable runs.

But, again, for hobby use, if you can hear what you want to hear, then what you have is likely good enough.
Unfortunately, LMR-400 has reached this mythical status as the be-all/end-all of coax cable. It isn't. It's decent stuff, but there are better cables out there. It's usually a pretty good step up for hobby use, it's fairly easy to work with, and the user gets some bragging rights. All OK, but there's are better cables out there….

I know what you are saying about better. I had several hundred feet of Hardline that was almost 1.5 inches in diameter. Now that was great cable. But no human could afford the connectors and the tool for putting them on. We used it to put a new cable on our VFD tower mounted antenna in Arkansas. But that stuff was a bear to work with for sure. And I always liked Belden cable myself. Call me old school; or brand stuck from the old days, but Belden was always there back in the day.
Thanks for your input I really appreciate the help
Bob

 

[owl9704a]

DIAMOND SP3000P

Lightning Arrestor DC - 3000 MHz 400 Watts PEP N Connectors

www.hamradio.com

That's one option (the one that I am using in front of my multicoupler). HRO has several others that will meet your needs.

Coax Loss Calculator | KV5R.COM

The higher the frequencies, the higher the line loss.

With 50 feet of RG-8, you are losing 25% of the signal at 150 MHz. LMR-400 17%

Same 50 feet of coax at 800 MHz? 54% loss with RG-8 versus 36% with LMR-400. Big difference.

Will RG-8 *work*? Sure. But LMR-400 will work better.

Now I have seen several of these and I stayed away from them because they said DC to 3000mz. I had no idea what they meant by DC. I always figured that was Direct Current, and could not figure what that had to do with radio frequencies. Could you explain that to me please? I would greatly appreciate it.
Bob

 

[mmckenna]

Now I have seen several of these and I stayed away from them because they said DC to 3000mz. I had no idea what they meant by DC. I always figured that was Direct Current, and could not figure what that had to do with radio frequencies. Could you explain that to me please? I would greatly appreciate it.
Bob

Some antennas require power for internal amplifiers:
-GPS antennas
-Satellite receivers
-Inline preamplifiers mounted at the antenna/Tower Top Amplifiers

You would need a lightning protector with the ability to pass DC power up the coax.
If you are not running an antenna that requires power/preamplifier, then you don't need a DC capable protector.

 

[owl9704a]

But the Diamond only says 3000 mz on it and no bottom frequency. That was what threw me off also. Hence the confusion about the DFC before the 3000
Thanks
Bob

 

[vagrant]

@owl9704a DC does mean Direct Current. It is often used to convey 0 to whatever frequency. Thus, DC to 3000 MHz would mean it covers an extremely large range. Slang for that is DC to daylight.

 

[owl9704a]

@owl9704a DC does mean Direct Current. It is often used to convey 0 to whatever frequency. Thus, DC to 3000 MHz would mean it covers an extremely large range. Slang for that is DC to daylight.

Now that is the language I can understand. Why don't they just say that on the package or site?
Thanks so much for helping me out here.
Bob

 

[vagrant]

No problem. My biggest obstacle when I started to get into the various radio related hobbies was trying to figure out what all the damn acronyms were.

 

[sonm10]

Unfortunately, LMR-400 has reached this mythical status as the be-all/end-all of coax cable. It isn't. It's decent stuff, but there are better cables out there. It's usually a pretty good step up for hobby use, it's fairly easy to work with, and the user gets some bragging rights. All OK, but there's are better cables out there….

Off topic, but what is better than LMR-400?

 

[mmckenna]

Off topic, but what is better than LMR-400?

There's a lot of stuff that is better than LMR-400, and no way I could list them all.

Times Microwave Makes LMR-600, LMR-900, LMR-1200 I'm running LMR-600 on my base antenna at home only because I have access to it as well as the tools to install connectors..

Then there's Heliax. I use various types at work, 1/2", 7/8", 1-5/8" Connectors get expensive and installation can be difficult.

And then you get into the serious hard line stuff used at TV transmitters.

Really depends on the application - length, frequency, amount of loss you are willing to accept, price….
LMR-400 is reasonably priced and a manageable size for most users. LMR-600 is getting a bit stiff and hard to run inside walls. The minimum bend radius starts getting pretty big. Heliax is expensive, stiff and connectors are expensive.

For most hobby users, there's a point where the drawbacks of the larger/more expensive coaxial cables start to outweigh the benefits. And as stated elsewhere, sometimes RG-6 is a good solution for scanner listeners.

 

[WA0CBW]

Hard line.

 

[TGuelker]

I am using a Polyphaser DT-NFF

https://www.polyphaser.com/type-n-surge-protector-3ghz-3ghz-gas-discharge-tube-dt-nff

It is for DC to 3 GHz