| Author |
Message |
    
Bigwheel
New member
Username: Bigwheel
Post Number: 2
Registered: 10-2005
| | Posted on Monday, October 31, 2005 - 12:59 pm: | 
|
I'm using RG8 coax on my beam right now but was wanting to change it out for something better.I using two 120' runs of it.Theres alot of different types was just wondering whats the best to use.Thanks |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 1802
Registered: 7-2004
| | Posted on Monday, October 31, 2005 - 3:05 pm: |
|
look for lowest db loss at 30mHz, highest % shield, & a double shield if possible. if on a beam with rotator, semi-flexible would be needed.
rg213
9086
9913f
lmr400 |
Wildrat
Intermediate Member
Username: Wildrat
Post Number: 207
Registered: 12-2003
| | Posted on Monday, October 31, 2005 - 3:58 pm: |
|
Tech808/Lon told me RG213 which Copper sells. I bought a 100 feet of it. I got it last week, looks good, it's somewhat flexible. Should be great. Go to the Copper store front and under categories press coax, then just look thru till you see RG213.
http://www.copperelectronics.com/cgi-bin/checkitout/checkitout.cgi?catalogSTORE:CKIE:prodC60-00012+
Wildrat
CEF674 |
Kid_vicious
Advanced Member
Username: Kid_vicious
Post Number: 767
Registered: 9-2004
| | Posted on Tuesday, November 01, 2005 - 12:04 am: |
|
you cant go wrong with LMR400. it cured all my TVI problems.
best coax ive ever had!
matt |
Deptuydog
Junior Member
Username: Deptuydog
Post Number: 13
Registered: 5-2005
| | Posted on Tuesday, November 01, 2005 - 12:59 am: |
|
Has any of the Techs evaluated the Belden 9913 50 OHM rg-8/u coax. I was told it was very low db loss and very well shielded. Iam looking for some good coax for a Imax 2000 antenna, and i was told that this coax would be very good for low loss db and TVI.I would welcome any ones comments. thank you |
Tech808
Moderator
Username: Tech808
Post Number: 8021
Registered: 8-2002
| | Posted on Tuesday, November 01, 2005 - 1:25 am: |
|
Bigwheel,
My suggestion would be the RG-213 from Copper.
Never had any problems with TVI running the S.I.W. 213 coax at our station here on our 2 Meter, 6 meter, 10/11/12 and my my Cushcraft R-5 antennas.
Lon
Tech808
CEF808
N9OSN
|
Tech808
Moderator
Username: Tech808
Post Number: 8022
Registered: 8-2002
| | Posted on Tuesday, November 01, 2005 - 1:38 am: |
|
Deputydog,
Yes I have, and I switched to the S.I.W. line of Coax about 20+ years ago from the Belden line of products.
S.I.W. Coax has the Same Excellent Quality but with a Lower / More Reasonable price. 
And S.I.W. is the Oldest Coax Manufacturer in the US.
All of the Coax that Copper stocks / sells is also Manufactured by S.I.W. (Superior Insulated Wire)
COAX
I would almost guess that I am the largest buyer of Coax from Copper now and I have never personally had a compliant on any of it that i have used myself or from any customers in the Last 20+ years since I switched from Belden to S.I.W.
Lon
Tech808
CEF808
N9OSN
|
Bigwheel
New member
Username: Bigwheel
Post Number: 3
Registered: 10-2005
| | Posted on Thursday, November 03, 2005 - 3:22 am: |
|
Thanks for the input everyone my coax is getting kinda old and I'm going to raise the beam up higher plus I'm have a little trouble with tvi. just looking for the best way to go |
Deptuydog
Junior Member
Username: Deptuydog
Post Number: 14
Registered: 5-2005
| | Posted on Friday, November 04, 2005 - 1:17 am: |
|
thanks for the reply lon, iam curious does the 213 and the 9913 coax have the same rating on the shielding? If i had acess to either one for free would you still recomend the 213?
thanks again i really to enjoy having a place to come to where i can ask questions and get many answer.
dave
deptuydog |
Bob_p
Advanced Member
Username: Bob_p
Post Number: 714
Registered: 7-2004
| | Posted on Friday, November 04, 2005 - 12:29 pm: |
|
deptuydog
Here's a link that can answer all yout questions
http://www.ocarc.ca/coax.htm
You select from the list which cable your interested in and it will give you exact cable loss for your run, combine your antenna gain and give you a very good idea of your erp is.
Most people recommend 213, but see what you think.
Hope this helps
Bob
CEF #362
KG6POG |
Silverfox
New member
Username: Silverfox
Post Number: 2
Registered: 3-2006
| | Posted on Thursday, March 30, 2006 - 2:10 pm: |
|
Well...I'm new here and have found this site to be a MAJOR help to me in beginning this hobby (even though I'm no spring chicken!) so....thanks everyone. I have a question regarding this coax issue...I have an Imax2000 (not up yet) and would like to use the very best coax possible. Eliminating tvi is a real concern. But, when I look at the good stuff, like LMR400, I am presuming that it is very stiff (I have no experience with the flexibility of any of these wires). How can I make a choke with such stiff wire?? Any suggestions on which GOOD coax to use and still be able to make a choke at the feedpoint? Frankly, I would like to use a double shielded coax (don't know which one that is) and according to the coax calculator I have, I guess I'm not too impressed with the RG213's loss figures. I would like the best shielded, lowest loss coax that will still allow me to make a choke at the feed point of the Imax2000. Thanks...this question has me perplexed.
Mike
aka silverfox |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1363
Registered: 9-2004
| | Posted on Friday, March 31, 2006 - 12:33 am: |
|
i use the LMR400 coax in the base setup and LMR240 in the mobile, and i can tell you that in my opinion, the LMR coax has a noticable decrease in TVI and vehicle noise over any other coax that ive used. i personally am a huge propenent of it.
the LMR coax is double sheilded, and IMO it makes the difference.
the LMR 400 really shouldnt be coiled around a form smaller than about 8". the big deal about the choke balun is that you use 18-21' of coax in your coil. the number of turns and the diameter of the coil are not important.
so if you can find a substrate that is 8 inches around, non-conductive, and weatherproof, you can use it.
you could make the coil out of different coax, (lmr240) and use barrel connectors to attatch it to your antenna and coax.
check out "chad" in the members pictures area.
he built a very nice one like this.
there is a product called LMR400ultra which is more flexible, but also more expensive.
in all reality, if your coax run is less than 100' just use LMR240ultra for the whole thing, balun and all. you will really like it.
the biggest deal involving your coax and interference is putting the ends on correctly.
if you dont have experience with this, you should have the company that you buy it from put the ends on for you. if you do them yourself, remember to solder in all four holes. if that doesnt make any sense to you; definitely have the coax supplier do the ends for you.
good luck,
matt |
Tech237
Moderator
Username: Tech237
Post Number: 256
Registered: 4-2004
| | Posted on Friday, March 31, 2006 - 12:59 pm: |
|
The bets coax is the bets you can afford. Personally I'd love to Heliax to every antenna I own and I regrte not being able to fit my 100ft lengths in my suitcase when I left Australia.
Right now I use RG-213 or RG-214 and RG-6 for one two meter antenna. |
Silverfox
Junior Member
Username: Silverfox
Post Number: 13
Registered: 3-2006
| | Posted on Saturday, April 01, 2006 - 3:09 pm: |
|
Thanks a lot Kid! And tech 237. My problem is that I will have a run of about 130 feet. Now...if I want to have 18 foot multiples I'm going to get up around 144 feet. THEN...if I want to do a choke I will be up around 162 feet!! This is going to get expensive not to mention the flexibility problem trying to do a choke with the ant coax. I'm thinking ....forget the choke and the multiples and just go with the 130 feet. I'm concerned about TVI with the neighbors TV ant but if I ground everything (still another problem) and use the LMR400 I SHOULD be ok. Maybe. The multiples of one wave length is up for debate among radio people anyway but I was under the impression that Solarcon actually recommended a choke. Boy, this stuff sure can get confusing. I would like to get on the air but I would also like to do everything right. The tough part is finding out what right IS. Thanks again, guys.
silverfox |
Road_warrior
Senior Member
Username: Road_warrior
Post Number: 1311
Registered: 7-2004
| | Posted on Saturday, April 01, 2006 - 11:06 pm: |
|
The Imax 2000 is close to having a perfect
SWR right out of the box. Not sure why your
worrying so much about these multiples for
your coax. LMR-400 is very stiff. If your
dead set on buying LMR-400. Also buy a short
piece of flexible coax which can be used to
form your choke and connect it to the LMR-400
with a barrel comnnector. |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1366
Registered: 9-2004
| | Posted on Sunday, April 02, 2006 - 12:34 am: |
|
hey silverfox, forget about all of that 18' stuff.
its just CB mythology. just trust me that if you install the antenna correctly, any length of coax will be just fine.
the biggest deal about TVI is not the antenna, its the radio!
if you clip the modulation limiter in the radio, or have someone do a "peak and tune", you will bleed on all kinds of stuff, and good coax wont help.
if your radio is left stock, and you buy a good low pass filter (upwards of $60), you will not bleed on your neighbors TV or phone.
if you do, then its because HIS TV or phone is cheaply made, and its not your fault.
in the interest of being neighborly, you could knock on his door, and tell him to turn on the TV to channel 2 or 5, and listen on the phone, and key the radio to see if he hears anything.
if so, you can probably correct the problem right at the TV or the phone. you can get a high pass filter for the TV, ($6 at radio shak). you can also buy filters that attach to the phone.
since you only have one neighbor to worry about, i think these are your best solutions.
what kind of radio are you going to use?
are you planning on using an amp?
is your radio room on the first or second floor?
dont panic! we've talked others through the same thing, and their stations are awesome!
check out "sinker" in the members pictures area. (lots of pics!)
he started out inheriting some equipment, the bug bit him, and now he has a tower in his yard!
there are also a bunch of threads directed at getting his station together.
if you do it like him, you'll be golden.
matt |
Bruce
Senior Member
Username: Bruce
Post Number: 3718
Registered: 9-2003
| | Posted on Sunday, April 02, 2006 - 8:21 am: |
|
We use lmr-400 at the jail for all our radio systems and I use it here at the house. |
Silverfox
Junior Member
Username: Silverfox
Post Number: 17
Registered: 3-2006
| | Posted on Sunday, April 02, 2006 - 11:47 am: |
|
Thanks again, Kid...and, by the way, Bigwheel...I didn't mean to hijack your thread. My apologies. Well, Kid, I have an original President Washington with extras and it appears there have been some tweaks done here and there. For some reason, the mike gain seems to be turned all the way up in the radio. We tested it at my friend's house and turning the mike gain knob on the radio seemed to have no effect so we had to turn down my D-104 to compensate. I may have a good tech I know about look into this. I would like to have more mike gain control at the radio and I don't want to get into my neighbors' stuff. I have more than one neighbor close by even though I live out in the country. I do have a Workman TVI 2K that is used that a friend gave me that I will be using if I ever get set up. I think the clarifier may have been slightly clipped on this radio too...not sure. That's why I want to go see this old tech and have him check everything out on my radio before I put it in service here. If I do get into the neighbors' electronics I want to know what all the possibilities are right from the start. I am aware of the low and high pass filters too. I will be operating from the first floor with my ant installed (if it ever gets up) at the opposite corner of the house. I am shooting for 54 feet to the bottom of the Imax so my coax run should be about 120 feet or a little more. This property sits very high so I don't plan on running an amp at this time but would like to set up for one if I should want to use one in the future. As it stands right now, I think I will go with the galvanized mast, use the GPK, use LMR400(or similar) with no choke and let 'er rip. Thanks again, Kid, for sticking with me on all my threads and questions. If I knew how...I would move all this to one of my threads. I feel badly that I horned in on Bigwheels thread.
silverfox |
