How much loss is caused with connectors?

[wb3j]

Probably a dumb question, but I'll toss it out for advice. I have a new antenna due to be delivered any day now. The coverage is said to be about 113 to 1000 mhz. Is a DPD scanner LP antenna.

I want to install it about 10 feet higher than my current antenna, which the new antenna is replacing. To do this I'll have to add about 10' of cable, which is 9913 cable. I'll have to add 2 additional connectors plus a barrel connector, so there will be more hardware instead of the straight run I currently have.

So my question is will the added connectors (2+barrel) and the extra 10' of cable negate the effort to raise the antenna? I'm in a deed-restricted neighborhood so when I installed my original antenna, I kept it hidden as possible. It's behind a chimney, so some of the signals may be blocked. At this point I don't care about the HOA, so if it's worth the effort to raise it I will. Most of the freqs I listen to is in the 154 mhz range, but the loss concern is 800 range.

Thanks..

Jim
wb3j

 

[WouffHong]

Is it worth it?

Probably a dumb question, but I'll toss it out for advice. I have a new antenna due to be delivered any day now. The coverage is said to be about 113 to 1000 mhz. Is a DPD scanner LP antenna.

I want to install it about 10 feet higher than my current antenna, which the new antenna is replacing. To do this I'll have to add about 10' of cable, which is 9913 cable. I'll have to add 2 additional connectors plus a barrel connector, so there will be more hardware instead of the straight run I currently have.

So my question is will the added connectors (2+barrel) and the extra 10' of cable negate the effort to raise the antenna? I'm in a deed-restricted neighborhood so when I installed my original antenna, I kept it hidden as possible. It's behind a chimney, so some of the signals may be blocked. At this point I don't care about the HOA, so if it's worth the effort to raise it I will. Most of the freqs I listen to is in the 154 mhz range, but the loss concern is 800 range.

Thanks..

Jim
wb3j

Unless the chimney is metal. metal-lined, or has very high flashing, the 10' of extra cable and 2 Connectors PLUS a barrel would most likely negate (or be almost negligible improvement to) any expected improvement from the 10' increase in elevation.

Also, the new connections will be semi-exposed to the weather and over time, corrosion WILL seep in and become lossy, but SO gradually that you might not even notice it happening.

BTDT.. )

73
Tom
W4NOV
NASA-KSC Comm-Lab Systems P.E. (Ret'd)
http://wouffhong.org

 

[DPD1]

Yeah, that would be my concern, is not so much the instant loss, but just having so many connections to go bad over time... Especially in cold weather areas. Wasn't there something I read about a change in law giving more power to people in HOA situations? Maybe try the short height then eventually get it up there where you really want it, the right way.

Dave
www.DPDProductions.com
Antennas & Accessories for the RF Professional & Radio Hobbyist

 

[rescuecomm]

Make them N type and the loss will be less than the PL259 stuff. A good rule of thumb is to avoid adapters and inline connectors like the plague. An example is using 5/8 hardline (1.7 db/100ft@400mhz) instead of 9913 2.7db/100ft@400mhz). If you have to use jumpers between the hardline and the antenna/radio on both ends (greater than 1 db loss per), you would have a better setup by just running the 9913 direct to both ends.

Or something like that?

Bob

 

[prcguy]

At VHF and above, added height is more beneficial than the slight loss you describe in connectors.
prcguy

 

[kb2vxa]

Oh good grief here we go again! Can't anybody on this forum READ??? Oh no, why bother looking for the answer that's been repeated endlessly when it's so easy to ask and add yet another useless thread to the archive?

 

[zguy1243]

Run a solid piece of cable, no barrels. I am not a fan of the 9913 coax due to weather issues with it. Google 9913+water and see what you get. I would go ahead and get the antenna out of the way of the chimney. Place the antenna above most really close obstructions such as the chimney. Weather proof your connections properly. Use 2 layers Scotch super 33 or 88 tape first over the connectors then layer of coax seal or butyl wrap and then another 2 layers of scotch 33 or 88 tape. This will make a proper weather proof connection. I take the approach to do it right the first time even if it cost more money now it will save money in the end when you have to go back and do it over. Take a look at some LMR600 cable too while you are at it.

Jody

Probably a dumb question, but I'll toss it out for advice. I have a new antenna due to be delivered any day now. The coverage is said to be about 113 to 1000 mhz. Is a DPD scanner LP antenna.

I want to install it about 10 feet higher than my current antenna, which the new antenna is replacing. To do this I'll have to add about 10' of cable, which is 9913 cable. I'll have to add 2 additional connectors plus a barrel connector, so there will be more hardware instead of the straight run I currently have.

So my question is will the added connectors (2+barrel) and the extra 10' of cable negate the effort to raise the antenna? I'm in a deed-restricted neighborhood so when I installed my original antenna, I kept it hidden as possible. It's behind a chimney, so some of the signals may be blocked. At this point I don't care about the HOA, so if it's worth the effort to raise it I will. Most of the freqs I listen to is in the 154 mhz range, but the loss concern is 800 range.

Thanks..

Jim
wb3j

 

[zz0468]

I'll second the comment about using 'N' connectors. Put 'em on right, and the loss is simply not a factor. And if you weather proof them properly, corrosion will not be a factor either.

Oh good grief here we go again! Can't anybody on this forum READ??? Oh no, why bother looking for the answer that's been repeated endlessly when it's so easy to ask and add yet another useless thread to the archive?

Of course they can't read. Where's the fun in that?

 

[wb3j]

Oh good grief here we go again! Can't anybody on this forum READ??? Oh no, why bother looking for the answer that's been repeated endlessly when it's so easy to ask and add yet another useless thread to the archive?

wow....maybe I did search but didn't find what I needed. Somebody's pad is full...

wb3j

 

[WouffHong]

Grinches abound.. And it ain't even december, yet. Sheesshh

wow....maybe I did search but didn't find what I needed. Somebody's pad is full...

wb3j

Pay no heed to the grinches, OM - They travel Forums looking for vague redundancies to show how "smart" they are and build their "postings" numbers. And seem to have no idea people POP the forum mail in the name of efficiency and may well miss the sometimes obscure, quasi-relevant post.

NOT to mention, your question was unique enough to warrant an honest question WRT the chimney.

The concept of friendly Elmering is a lost art around here, unfortunately. :roll:

73 (No CB "73's")

Tom

 

[radiopro52]

What would be the total length of the coax with the extra 10'? If possible, go with LMR400 or above. I use LMR400 (50 foot length) and it does wonders.

I have the same antenna you will be getting. It has a female N connector on it, so make sure the end of your coax has a male N connector. My situation required an adapter to be added to convert PL259 to N male. With it, the performance is still quite good. I think I read somewhere that each adapter/connector has about 0.5 db of loss. Not too much but it can add up.

Finally, if you don't currently have a rotator, I'd recommend you get one for this antenna if possible. It really improved performance for me to be able to point exactly where the signals come from. It can make quite a difference.

 

[wb3j]

Thanks for the replies and opinions (most). I don't remember the total length of the 9913 cable, as I installed it several years ago. I'm guessing it's a 70' run.It was done when the house was built, and it snakes through a wall, into the attic, through the roof and up along the chimney, which is a metal-lined and vinyl sided type for a gas fireplace.

Because of the way the cable is routed, there isn't an easy way to replace it with another type of cable. The only option is to remove the existing antenna and put the new one in it's place, or add a splice to enable the height adjustment.

'73
Jim
wb3j

 

[DPD1]

Jim, if you decide to stick with what you have, I could possibly make you up a longer feed cable that would replace the original cable on the antenna. At least that way you'd eliminate some of the connections. If you're handy, it's not hard to do. I would have to charge a fee for that, but nothing outrageous. We could have worked it out that way to begin with, but I didn't know the situation. Email me if you want to go for that.

Dave
www.DPDProductions.com
Antennas & Accessories for the RF Professional & Radio Hobbyist

 

[prcguy]

Adding extra coax using two male N connectors and a double female adapter is less than 0.1dB loss @ 1Ghz for all the connectors, so its good to stay with N type everywhere in your system if possible.
prcguy

What would be the total length of the coax with the extra 10'? If possible, go with LMR400 or above. I use LMR400 (50 foot length) and it does wonders.

I have the same antenna you will be getting. It has a female N connector on it, so make sure the end of your coax has a male N connector. My situation required an adapter to be added to convert PL259 to N male. With it, the performance is still quite good. I think I read somewhere that each adapter/connector has about 0.5 db of loss. Not too much but it can add up.

Finally, if you don't currently have a rotator, I'd recommend you get one for this antenna if possible. It really improved performance for me to be able to point exactly where the signals come from. It can make quite a difference.