Re: [Repeater-Builder] Re: 75 to 50 ohm match
It's nice that you had good SWR but so does my dumb load. Do you sweep it with something like a site master? Be neat to see. Russ, W3CH - Original Message - From: randy kisthardt [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Wednesday, January 21, 2004 12:08 AM Subject: [Repeater-Builder] Re: 75 to 50 ohm match I have been using catv hard line for 10 years and when i first used it i made some matching transformers from copper pipe and compared it to the line with out and didnt see aney differance swr or power or how well the rx worked i still use it have several runns of differant lengts and sizes and it works great never a problem but i might just be luckey A old ham told me if you never tell a transmiter its 75 ohm cable it will never know the differance . so i never told my radios what i had hooked up to em like the one guy said the mis match isnt that bad for me the only chalange is the connecters good luck AG4ZQ Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/ Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] wavetek ct systems 3000b
hi guys i have a wavetek 3000b service monitor and it has stoped working no receive and no generate .I have found the high frequency synth is not generateing the frequency output it should be and i have found the F100102 ic chip has a 1 meg signal up to the final gate but there is no output to the sampler's diode bridge .can anyone advise me about this chip and possible replacements if available. thanks ian Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re[2]: [Repeater-Builder] Re: 75 to 50 ohm match
I have the same experience. 75 ohm stuff works great. The transformers don't seem to be necessary for ham projects on two meters and above. Return loss takes care of most SWR. Dave __ Reply Separator _ Subject: Re: [Repeater-Builder] Re: 75 to 50 ohm match Author: Repeater-Builder@yahoogroups.com at Internet_mail Date:1/21/2004 5:29 PM I can vouch for this,found no discernable difference on VHF between a run of 7/8 Andrews and a run of jacketed CATV aluminum. Identical performance,cheaper price and no matching stubs.73,Lee,N3APP - Original Message - From: Dexter McIntyre W4DEX [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Wednesday, January 21, 2004 10:05 AM Subject: Re: [Repeater-Builder] Re: 75 to 50 ohm match I have seen 75 ohm cable work well with 50 ohm systems. The slight loss due to VSWR is offset by less loss in 75 ohm over 50 ohm for the same size cable. If one wants to trim the cable to provide a perfect match I would suggest this method. Measure the power at the output of the transmitter into a 50 ohm load. Connect the 75 ohm coax and move the wattmeter and load to the distant end of the cable. If the power measured here differs much from the first measurement less the speced loss of the cable then trim the cable length to optimize the power. I think that trimming the cable for best VSWR at the transmitter end but external to the transmitter may not give a true indication of what the transmitter is loading into. Dex Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/ Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] wavetek ct systems 3000b
At 12:49 PM 1/21/2004 -0600, you wrote: I have two Wavetek CT3000B service monitors. One works OK, the other has a problem in the scope. I would like this fellow's name to see what it would cost to bring one or both up to snuff. ---If anyone gets his contact info, I'd like it too. One of my level switches slipped a notch, so it actually displays 1 more than it should for a digit Ken -- President and CTO - Arcom Communications Makers of state-of-the-art repeater controllers and accessories. http://www.ah6le.net/arcom/index.html Our new Repeater Audio Delay (RAD) board is now shipping! Compatible with many controllers! AH6LE/R - IRLP Node 3000 http://www.irlp.net Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] wavetek ct systems 3000b
To the Group I note your info about the guy in Indianapolis repairing Wavetek service monitors. I would greatly appreciate his name and contact info as I have a model 3510 generator I am unable to get a tek manual for. This person might have such a manual as the Wavetek factory was there when they were in operation. I would be willing to buy, borrow or copy a manual. Without a manual my generator is useless because I have no Calibration procedure. Thanks de Tom Manning, AF4UG [EMAIL PROTECTED] ka9gix wrote: there is a guy here in indianapolis that repairs and calibrates those things. if you like i will track him down to see if he can help you. - Original Message - From: ian wells [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Wednesday, January 21, 2004 6:56 AM Subject: [Repeater-Builder] wavetek ct systems 3000b hi guys i have a wavetek 3000b service monitor and it has stoped working no receive and no generate .I have found the high frequency synth is not generateing the frequency output it should be and i have found the F100102 ic chip has a 1 meg signal up to the final gate but there is no output to the sampler's diode bridge .can anyone advise me about this chip and possible replacements if available. thanks ian Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/ Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/ Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: 75 to 50 ohm match
I have no personal experience with aluminum TV line, but I will relate what Joe Reisert, W1JR, wrote in Ham Radio magazine years ago. Joe was an avid V/UHF dx'er and moonbounce'er and at one point he dismantled all his arrays and measured all the various feedlines and phasing lines, most of which had been up for years. They were a mix of various sizes of Heliax and TV line. Without exception, the Heliax met new specs, and the TV line didn't. His conclusion was that he wouldn't use any more TV line. Now because of his application, he was concerned with fractions of a db. Repeater service may not always be that demanding in that regard. But personally I think Heliax or equivalent is worth the price. Roger Grady K9OPO Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] wavetek ct systems 3000b
Please add my name to the request for service on a Wavetek. Have a 3001 with a problem. Thanks, Gary K2UQ Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: 75 to 50 ohm match
Everyone seems to have the right idea, therefore, another reply probably isn't necessary.. However.. If we're going into the testimonials, I am using 200 feet of 1/2 inch 75 ohm aluminum on a 440 MHz repeater with no means of matching. You can effectively build a matching stub with 60 whatever ohm coax but unless you have the materials readily available, it's not worth the trouble (tried it once myself).. Another fellow mentioned something about the impedance repeating itself if the length of the feedline was just so. This is true. If the electrical length of the hardline was a multiple of an EVEN half wavelength, then you will see a mirror impedance of the antenna (50 ohms). However, if the length of your feedline just happens to be an odd quarter wavelength multiple, you have inadvertedly created a matching transformer which changed your 50 ohm antenna into a 100 ohm impedance at the other end of the feedline. One says to put a watt meter in line, then trim the coax until you get a good match. But take the watt meter out of line and you have altered the length of the cable once more and without careful calculation, your efforts are trashed. The worse thing that could happen is you have a mismatch with an impedance of 100 ohms at the end of the feedline going into your duplexer. If your VSWR was 2:1 then you're just over 10 % reflected power. Not that big of a deal. In fact, since 75 ohm feedline has a smaller center conductor, the loss is actually less than 50 ohm of comparable size due to less capacitance to the shield, and less surface area actually touching the dielectric. The point is, the few tenth's of a dB you may lose by running mismatched cable is made up in the end because the 75 ohm cable has a few tenth's less loss. You'll never know the difference. Don't change a thing. In fact, most of the CATV hardline has a sticky dielectric which repels moisture. 73, KC4FWC http://www.w4dex.com/kc4fwc/443825.htm --- In Repeater-Builder@yahoogroups.com, k9bf [EMAIL PROTECTED] wrote: I have a repeater attached to 300 feet of 75 ohm CATV hard line. I believe one can match using a length of 62.5 ohm coax, but how long and where to get it? The repeater is on 443.450 thanks Ben K9BF Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
