Re: Topband: Adding connectoirs to CATV Hardline
Plumbing parts work, but the problem is that there is a lot of catv hardline that is an odd size. For example, I have some 0.412 inch diameter cable and some 0.540 inch cable. That is what motivated me to learn how to use pin connectors. Tor N4OGW On Thursday, June 4, 2020, 2:00:38 PM CDT, wrote: Hi Guys, There is an article in one of the ham magazines from years ago that describes how to make an adapter from brass tubing compression sleve fittings (from auto parts store) that adapts from 1/2 inch CATV Hardline cable to UHF male connectors RG-8 size. Anti-oxidants required. I have been doing this for years with no problems at 1500 watts. There is a pair on my 80 meter 4-square as we speak. Its been so long that I have since forgotten where the article was. Perhaps an internet search would bring it up. I would write something up but I have my hands full at the moment with cleaning up after a tornado like storm with 100 MPH winds that went right over my house. Minimal damage except for the top 1/3 of my 160 vertical and lots of tall trees down in what's left of the yard. All else is fine with nothing I can't repair. Good luck. Lee K7TJR Culver OR Clamps do work ok with CATV hardline, but you have to be careful as it is very easy to crush the hardline. Also, waterproofing is always a pain. As W7WKR posted, I also adapt pin connectors, which are the standard way of terminating catv hardline. Here are some comments: Pin connectors have the same thread size (5/8") that is found on so-239s or N connectors. They are fairly cheap to buy new or can be found on ebay. One difficulty with pin connectors compared to many other hardline connectors is that it is nearly impossible to install them on catv hardline unless you have a coring tool of the right size to fit the hardline. This is because the pin connectors clamp onto the shield from both sides, so you have to completely remove the insulation from the hardline for 1-2" back up into the cable. Coring tools are > $100 new, but I have found them used for $20-$40. The used ones are often pretty worn out: however, with care you can sharpen the cutting parts with a file or stone, which makes a big difference. It can also be tricky to figure out how much center conductor you need sticking out for a given pin connector- some of the connectors have little tick marks on the outside that show the correct length to cut the center conductor. Once you have the pin connector on, then: 1. For type N: the body of a "clamp" type N connector will screw directly onto the pin connector (discard the smaller clamp part with male threads that normally goes on the RG-8). I just cut the pin to length and file the end down to a point. You do have to be careful that the point is not too wide, otherwise it might break the female contact. 2. For UHF: there are similar clamp-type UHF connectors available with the same 5/8 thread in the connector body. Here is one example: https://www.w5swl.com/Coax-Connector-UHF-Female-Clamp-fits-RG-8AU-RG-213-Series-Cable--by-W5SWL_p_466.html just cut the pin to the right length, solder on the center female connector, and screw the body on. 3. You can also just drill a hole in a metal box and attach the pin connector with a nut meant to go on SO239s. There are also splice connectors to join two pieces of hardline. These are nice because they don't require any waterproofing. There are also some that end in an F connector instead of a pin. Tor N4OGW r _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Adding connectoirs to CATV Hardline
Clamps do work ok with CATV hardline, but you have to be careful as it is very easy to crush the hardline. Also, waterproofing is always a pain. As W7WKR posted, I also adapt pin connectors, which are the standard way of terminating catv hardline. Here are some comments: Pin connectors have the same thread size (5/8") that is found on so-239s or N connectors. They are fairly cheap to buy new or can be found on ebay. One difficulty with pin connectors compared to many other hardline connectors is that it is nearly impossible to install them on catv hardline unless you have a coring tool of the right size to fit the hardline. This is because the pin connectors clamp onto the shield from both sides, so you have to completely remove the insulation from the hardline for 1-2" back up into the cable. Coring tools are > $100 new, but I have found them used for $20-$40. The used ones are often pretty worn out: however, with care you can sharpen the cutting parts with a file or stone, which makes a big difference. It can also be tricky to figure out how much center conductor you need sticking out for a given pin connector- some of the connectors have little tick marks on the outside that show the correct length to cut the center conductor. Once you have the pin connector on, then: 1. For type N: the body of a "clamp" type N connector will screw directly onto the pin connector (discard the smaller clamp part with male threads that normally goes on the RG-8). I just cut the pin to length and file the end down to a point. You do have to be careful that the point is not too wide, otherwise it might break the female contact. 2. For UHF: there are similar clamp-type UHF connectors available with the same 5/8 thread in the connector body. Here is one example: https://www.w5swl.com/Coax-Connector-UHF-Female-Clamp-fits-RG-8AU-RG-213-Series-Cable--by-W5SWL_p_466.html just cut the pin to the right length, solder on the center female connector, and screw the body on. 3. You can also just drill a hole in a metal box and attach the pin connector with a nut meant to go on SO239s. There are also splice connectors to join two pieces of hardline. These are nice because they don't require any waterproofing. There are also some that end in an F connector instead of a pin. Tor N4OGW On Wednesday, June 3, 2020, 8:25:09 AM CDT, Rob Atkinson wrote: For 160 m. frequencies, connectors on hardline that preserve the geometry (Z) of the line aren't needed. You can dress the line (i.e. strip back the jacket and dielectric) and make connections to transmitters and loads with copper strap that's wrapped around the center and shield and held with brass nuts and bolts or hose clamps. Use brass clamps if working with aluminum. 73 Rob K5UJ _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Hi Z amplifiers for 160m
Chris, I just finished making my own set of amplifiers derived from the YCCC design but using SMD components. I used an AD8045 (SOIC-8 size) instead of the 8055 and added a voltage regulator. They have replaced a set of the original Hi-Z amps (the ones in the black mini-boxes with metal covers) in my hexagonal array. I don't have a way to directly compare the performance of the new amps with the old ones, but so far they seem to work well. Tor N4OGW On Wednesday, March 11, 2020, 8:29:33 AM CDT, GEORGE WALLNER wrote: Chris, Assuming a trans-impedance amplifier, "unity gain" is enough (with reasonable size elements). Noise and IP3 are far more important. Lightning and surge immunity are also important. Also, isolate the amp from common mode noise travelling on the feed-line. Filter the power supply well. Use an F connector (a high quality one that can be torqued.) GL and 73, George, AA7JV/C6AGU On Wed, 11 Mar 2020 11:33:34 + Chris Moulding wrote: > As well as being a radio amateur (G4HYG) I also run a small business > designing and making radio equipment (Cross Country Wireless). > > Recently I've been asked by a radio contest group to see if I can redesign > the YCCC Hi Z amplifier using modern components and using similar mounting > arrangements to our Loop Antenna Amplifier. > > The first prototype using surface mount components is working well. > > So far I've not build an array of antennas but that will come later when the > production boards arrive. > > The prototype uses a unity voltage gain amplifier and a BNC connector. > > I've a couple of questions for others on the list with experience of running > vertical receive arrays: > > Is a unity voltage gain amplifier OK or do you think it needs more gain for > long coax runs? > > At present I'm using a BNC male connector for the output. Would an F type > connector be more compatible with existing antenna arrays. > > 73, Chris G4HYG > > _ > Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
