Soldering Connectors ....

[CookeCityScanner]

In an attempt to fix a problem Im having and also to setup a new transceiving unit I did some soldering today.

If you have read my other two posts Im brand new to this hobby and Im jumping right in with both feet. It just took me a while since I dont have proper stripping tools for the "9913 type" cable but I got my first N soldered on. Ive never soldered anything before in my life. It seems to be solid though and a simple concept.

Ive got an ohm/volt meter which I know how to use for work with standard electrical work which I do but Ive never used the ohm side of it . I know that my connection is good because I get a signal when I touch both ends of the cable. Its never 52 ohms though its all over the place. Its like this on all my cable though. This is my own stupidity though, Im just happy i know Ive got current flowing through.

Ive got all the tools for standard rg6, sure wish they worked on this stuff

anyway are there any sites for soldering tips using these type of connectors or guides etc. Thanks for the help.

 

[Al42]

I know that my connection is good because I get a signal when I touch both ends of the cable. Its never 52 ohms though its all over the place. Its like this on all my cable though.

It's 52 ohms impedence at RF frequencies. Between the center conductor and ground it should be infinite. Between the center conductors from one end to the other shouldn't be more than a couple of ohms.

anyway are there any sites for soldering tips using these type of connectors or guides etc.

http://lists.contesting.com/archives/html/Towertalk/1998-07/msg00848.html for how to cut the cable without special cable cutters.
http://www.seits.org/repeater/tuneup4.htm

However, you may not want to bother with N connectors - http://www.k1ttt.net/technote/connloss.html

 

[CookeCityScanner]

Good I tested the antenna (speciallized yagi tuned to 440-470mhZ) with my connections and it came in GREAT. Yes it was at short distance but I believe my work was good then.

On this antenna I used the rest of the 9913 that I didnt need for that Diamond Discone setup on that other thread. I went and attached (soldered) a new UHF to BNC on the end of that so now there is no coil at all just the proper length of wire. STILL DEAD. Thats dissapointing. I guess I need to test the wire out to see if anything carries through it.

Thanks for the tips/links.

 

[DaveH]

It's 52 ohms impedence at RF frequencies. Between the center conductor and ground it should be infinite. Between the center conductors from one end to the other shouldn't be more than a couple of ohms.

Some antennas normally have a dc short circuit (the kind you can measure on a dc ohmmeter), so you should check the cable before connecting to the antenna. Then check after connecting it. If the antenna should be a short, you should see that between the center conductor and shield.

Dave

 

[Al42]

It's 52 ohms impedence at RF frequencies. Between the center conductor and ground it should be infinite. Between the center conductors from one end to the other shouldn't be more than a couple of ohms.

Some antennas normally have a dc short circuit (the kind you can measure on a dc ohmmeter), so you should check the cable before connecting to the antenna. Then check after connecting it. If the antenna should be a short

Which a discone shouldn't.

 

[CookeCityScanner]

Youve got to try and keep it on my level. Im learning a lot but its still day 2

 

[SAR923]

If I've read your messages correctly, you now have two antennas that you're using this "9913" clone cable for and neither antenna gives you any signal. Assuming your connections really are good, this cable must have either a bad conductor or multiple breaks because it's been bent too many times. Belkin 9913 is certainly the best cable but Radio Shack RG6 does a very creditable job and it's much easier to use since it already comes with "F" connectors on both ends. You might think about getting some and seeing if it will do the job for you.

 

[CookeCityScanner]

Ok first of its not Belkin... I thought it was but its a "9913 type" cable. Secondly Im only having problems with one antenna. I got 100' of the 9913 and connected it to the ScannerMaster (Ive been saying Diamond but now that I look I think SM makes their own) discone. Anyway That was dead. I had about half of that coiled up because I didnt need it so I cut that part off basically cutting the cable in half. I then soldered on an N connector on that cut end and attached it to a new yagi I have for custom purposes. THAT connection and wire and antenna works FINE. I soldered a UHF w/ BNC adapter onto the other end of the cut wire still hanging from the Discone and its still dead. So either something in the wire is bad or antenna.

You guys keep saying just use RG6 and I will. I thought it wasnt good because of the different impedance but Ive got the tools for that job and itd be GREAT if I could use that stuff.

 

[N_Jay]

You guys keep saying just use RG6 and I will. I thought it wasnt good because of the different impedance but Ive got the tools for that job and itd be GREAT if I could use that stuff.

Don't worry about the minor impeadence mismatch.

wideband receive antannas are not constant inpeadence anyhow, so there is little difference.

Even is it was a perfect 50 ohm at both ends, the loss would be less than 1 dB.

 

[kb2vxa]

Hi CCS and all,

OK, you have one working antenna and one not, fair enough. First, take down the discone and ring through the coax with the ohm meter. Continuity wise you should read a dead short (less than 1 ohm you can't measure on an ordinary meter) and open from center conductor to outer braid.

Next, do the same for the discone antenna, center to "ground" should be open circuit. Now go looking for the insulating bushing you lost when you assembled it. (;->) BTW, a Yagi may or may not show DC continuity between "hot" and "ground" depending on the matching system. Most use series fed gamma matching which shows open but some use shunt feed for something other than 50 ohms when a stacked system is used. Likely yours like most is series fed meaning the gamma rod has an integral capacitor, usually a rod inside a tube with insulating material between.

Sorry I can't be more helpful but I'm not there and doing diagnostics by remote control is difficult at best. Last but not least, for the past 30 years all I have ever used to strip coax is a sharp knife, slice carefully, don't whittle with it. (;->) BTW, no messing around with the braid when you cut down the dielectric, slice right through it down to the center conductor, that's the test of a good knife. Mind the whiskers, that's where a strong lamp and magnifyer come in handy to find potential shorts.