Can I use Broadband coax?`

[EdHotmar]

(edit at 0326/27-July-2006) Sorry this kind of got dragged out...

I have this cable and would like direction with the abiltiy to use this for may scanner. Obviously, I am not knowledgeable in this area. I am what I think is called a "Newbie" I suppose. I have some rg-58 A/U, rg-59U, RG 8X and RG-8U. I also have some of this.

http://dominoportal.commscope.com/CommScope/Eng/specsheets2.nsf/e95a7b49c73b793285256d980045d994/da5121c22417ec0b85256760004d7c30/$FILE/F677TSVV.pdf

It is as follows off CommScope's specsheet page:
F677TSVV
75 OHM Coaxial Cable
CATV (ETL)
The link above give all the description of it. I don't know if I am allowed to cut and paste it here for you to see. That is the reason that I pul the http:// link up to go to it.

If anyone would be kind enough to check it out for me and give me the run down on it I would appreciate it. I am thinking of useing it if I can. If not, then which one of the ones I noted above would be the best to use.

I will be running about 50' or so. Not quite sure, but for sake of aurgument, let's say 50-60'
BC796, Discone, and I can go about 20' high. It will be more like 18 or 19 as 20 would extend the second section all the way out and would not be very sturdy I am afraid.

I only will be using it for police/fire/ambulance etc. plus I am still trying to learn how this damn trunking works so that I can get my local services programmed in istead of just the surronunding areas. So like I ask, any help will be appreaciated. If you would email me the info or that you posted I would appreciate that even more as I don't have much time lately to surf and see if anything has been put up. Please just send a quick note to me at
>>69FLH10XX at campus dot com<<. I check that email throughout the day and will see any thing sent to me there telling me of any post that may be up in answer to my "plea" lol

Thank you very much....

 

[Napalm]

I think it's also called RG6. I'd go ahead and try it. Get some F connectors + F to BNCs to fit the back of your radios.

 

[jlh]

it will work fine, edhotmar

 

[mass-man]

Napalm is CORRECT! Go ahead and give it a try!!! If it works, GREAT! If you don't hear what you think you should, then swap cable.

Correct antenna, heighth, coax, etc. is unfortunately an experiment for most of us. If we all could afford commercial grade antennas, LMR-400 and a tower to support the antennas, life would be good. Most of us can't!

So put the antenna up as high as you can...feed it with the coax. If you hear what you want to hear, and you have excess cable lying about, cut it off and you might hear just a little bit better.

Antenna experimentation is almost as fun as searching out odd and unknown freq. and TG's.

 

[prcguy]

You mention having some RG-8, which would usually be the best choice depending on mfr and quality. If it&#8217;s a newer low loss foam dielectric RG-8 type go with that, otherwise the Commscope cable is a good quality 75ohm RG6 and has loss specs similar to RG-8. What kind of connector is on the Discone? RG-8 will connect directly using a PL-259 or N and will only leave you with a single adaptor at the radio end. RG-6 will usually need 2 adaptors at the antenna end leaving more stuff to waterproof, etc.
prcguy

 

[EdHotmar]

The Discone is a PL-259...

 

[poltergeisty]

Could cable splitters be used with the standard cable like RG-6 to add more than one ant.?

 

[N_Jay]

Could cable splitters be used with the standard cable like RG-6 to add more than one ant.?

Sure, for most people more then one antenna is a random shot in the dark approach.

The splitter makes it no worse.

 

[prcguy]

Yup, but are you wanting to combine two directional antennas to increase gain and directivity or two omni antennas? Directional antennas can be easily combined but you need to have critical lengths of coax between the splitter and each antenna. If you randomly combine two omni antennas, same or different style, signals can arrive at the receiver at different times and actually degrade or cancel each other out. It&#8217;s a crapshoot on what will happen. If you want to combine antennas for different bands you can use a Diplexer or Triplexer and get good results.
prcguy

 

[poltergeisty]

Ok, would it make no difference either if I ran more than one scanner feed from one antenna spliced with a cable splinter?

I currently don't use RG-6 but if I can find a cheaper approach to connecting more than one scanner to an antenna, I'm all for it!

 

[poltergeisty]

I guess this classifies as one of those "dumb questions".

 

[prcguy]

No dumb questions here. If you already have 50 ohm coax and your happy with it, shop for a 50 ohm 2-way divider on Epay. I’ve seen nice ones (10-1000MHz) with BNCs go for just a few $s. I would not change over to RG-6 just to use TV type dividers. Whatever passive device you use to divide the signals will loose at least 50% of your signal splitting 2 ways. With cheap TV splitters it will be more at 800MHz. If you need to split more than 2 ways I would look for an amplified divider made specifically for VHF/UHF monitor use by companies like Stridsberg Engineering. Their specs are not stellar but most people seem to be happy with them.
prcguy

I guess this classifies as one of those "dumb questions".

 

[Al42]

Ok, would it make no difference either if I ran more than one scanner feed from one antenna spliced with a cable splinter?

I currently don't use RG-6 but if I can find a cheaper approach to connecting more than one scanner to an antenna, I'm all for it!

It's like filling more than one quart container with one quart of coffee. Sure you can do it. What you can't do is fill each container with a quart of coffee. With 2 containers you get a little less than 1/2 quart in each (some "spills"). With 3 containers you get a little less than 1/3 quart in each.

Now, if you only want 1/3 quart of coffee in your container it'll work. but you can't put a quart (the full signal coming from the antenna) into each of 3 containers (3 scanners) at the same time. (The spills are the loss in the splitter.)

People will tell you that using an amplified splitter will help, but an amplifier will amplify the noise just as much as it amplifies the signal, so it really doesn't solve the whole problem. How well you receive a signal isn't only a matter of how strong it is, with FM it's a matter of how far above the noise it is.

 

[poltergeisty]

Good explanations. Thanks.

SO, I guess instead of trying to feed more than one scanner with one antenna, I'll just go head and use separate antennas.

Now I have to wonder if I had, say a 2 meter antenna and a 800 MHz antenna connected to the the scanner/s this too would effect performance?

I guess it would regardless of the antennas I use for specific bands.

I wonder if I'll still "spill" as much "coffee"? Due to the specific banded antennas, maybe, I'll spill less?

I just happen to think about high pass/low pass/notch filters, never used them. How would these fare in this situation?


I'm guessing that I'll still have spillage, just not as much as before.