RE: [Repeater-Builder] Re: duplexer isolation and reciever noise budget
I don't have a coordinated pair at this time, and someone on my local repeater mentioned something about uncoordinated/unprotected/test/community pairs in 144 and 440 bands.. so if you know what they are, that's probably where this repeater will live until I get coordinated (if I get coordinated - NE Texas is pretty packed up).. So until I get more information, I guess I should be focusing on isolating the 2 digital rigs. _ From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of skipp025 Sent: Friday, October 05, 2007 4:51 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: duplexer isolation and reciever noise budget Before I give you an answer I'd want to know where the repeater is going to be placed. Operation in the 146 and higher portion of the band is going to be a heck of a lot easier than a repeater in the 145 segment. both aprs and winlink radios on the same antenna are going to require some serious and unique protection methods. To talk about the cavity size question/issue... you'll notice the cavity Q is much higher for most larger diameter cavities. So pretty much anything you are going to want to hunt down is going to be the larger high Q cavities on the order of 8 inch min typical. s. John B [EMAIL PROTECTED] wrote: I'm attempting to design a system that will have a VHF repeater (freqs not yet determined) sharing an antenna with 2 packet radios (APRS on 144.39 and Winlink on 145.05, either of which may be active as a digipeater at any time). I'm currently considering a bandpass-only quadplexor to isolate the radios from each other.. each radio running through a bandpass filter tuned to its frequency only (that includes the transmitter and receiver for the repeater), on the theory that it is a lot easier to pass one frequency than it is to reject 3 others. Assuming that none of the transmitters run more than 50w, how many DB down do I need to be outside of the passband to minimize desense for any of the 3 receivers ?? Any other suggestions on how I might handle this hookup would be greatly appreciated. I'm nearing completion my trailer-mounted 40ft crank up tower, and I'm having some problems budgeting space for a filtering system with 12 bandpass cavities without cutting into general cargo space.
[Repeater-Builder] Sinclair Duplexers
If you need VHF duplexers see this set of Sinclair Q2330E 6 cavity duplexers on eBay. Mick, KB4UPI -- I pledge allegiance to the flag of the United States of America, and to the republic for which it stands, one nation, UNDER GOD, indivisible, with liberty and justice for all. - Never own anything you aren't willing to drill a hole in. See our web site at http://LindleyOnline.com
[Repeater-Builder] Crystal Exchange
I am looking for contact information on the guy that exchanges channel elements (for a modest fee). I have Motorola Micor elements that I want to exchange. The particular one I am thinking of has been around for a lot of years and has a humongous inventory. Does this ring a bell? Any info appreciated. Thanks Doug North Bend, WA
RE: [Repeater-Builder] duplexer isolation and receiver noise budget
OK - the problem may have just gotten beyond easy solution... I just checked with the repeater coordination folks, and if I'm going VHF at all, I'm looking at a year or 2 for a coordinated pair in this area, which pushes me off to the 145.250 / 144.650 backyard repeater pair.. which puts me smack dab in the middle of the APRS and winlink frequencies :-) So if I'm going to attempt that, I'm going to have transmitters on 144.39, 145.01-09, and 145.25.. and I have to protect receivers on 144.39, 144.65 and 145.05 At this point I'm probably going to stick the repeater up on the UHF backyard pair (once I find out what it is !!) _ From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Joe Montierth Sent: Friday, October 05, 2007 7:43 PM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] duplexer isolation and receiver noise budget I think you need to identify what your priorities for this project are. If it's not cost, then there are several ways to do this thing. It seems like your biggest concern might be physical size of the cavity package. If that is the case, what I would do would be to get a repeater pair in the 147MHz range, the upper meg of 2M. If that is possible you could get two 2M duplexers, one for the 147 repeater, and another for the 144/145 frequencies. Now you have everything combined into two antenna ports, one for the 144/145 stuff and one for the 147 repeater. Next, you need a way to combine these two ports into one antenna. This could be done with several notch type cavities, or a wideband pass type duplexer. The duplexer solution would be easier, and take less rack space. There is a company called DCI that can build you a custom BP duplexer that would cover the 144/145 on one port and 147 on the other. Should be able to make it with 60 to 70dB of isolation between the two ports, and about 1.5 to 2 dB of insertion loss. Now depending on the duplexers that you choose, it should all fit on less than one standard 6ft rack, maybe even half a rack. You should end up with 75+ dB of isolation from any port to any other, and probably about 3 to 3.5 dB of insertion loss, which is a little much, but acceptable for this type of operation. The bad news is the cost. This could be in the 6K range, give or take, maybe as little as 3K, if you can shop around for the 2 duplexers, and are not overly concerned about the size. Contact www.dci.ca and tell them what you are trying to do, and what they could engineer a solution for the wideband duplexer part of this. They probably can't do anything for the 2 close spaced pairs, and that is where Telewave, dB Products, Sinclair, TXRX, etc will come in. It should work out OK, but using two antennas would be simpler and cheaper, but maybe that isn't an option. Joe --- John Barrett [EMAIL PROTECTED] mailto:ke5crp1%40verizon.net net wrote: Finally found some good diagrams for a 3 cavity bandpass filter at Telewave, and it looks like I can get 80db down with 6db of insertion loss using 5 cavities, which may be acceptable as I can make it up at the antenna if needed. Then it seems I can get the last 10db (if not more) by kicking up to a 6 or 8 cavity to steepen the skirts. http://www.telewave http://www.telewave.com/pdf/TWDS-5012.pdf .com/pdf/TWDS-5012.pdf So bandpass CAN be made to work. the question then becomes: Is there a way to do it with less than a dozen cavities ?? Using notches seems to be counterproductive as I would need 2-3 notch cavities per radio per frequency to notch (call it 3 recievers vs 2 transmitters, or 6x3 - 18 reject cavitites) Do I really need the cavities on the repeater transmitter (which will never be used for receive). might not a Wilkinson splitter/combiner do the trick, bringing at least that one transmitter down 20db before hitting the cavities for the 3 recievers Bring on the other ideas :-) _ From: Repeater-Builder@ mailto:Repeater-Builder%40yahoogroups.com yahoogroups.com [mailto:Repeater-Builder@ mailto:Repeater-Builder%40yahoogroups.com yahoogroups.com] On Behalf Of Eric Lemmon Sent: Thursday, October 04, 2007 9:50 PM To: Repeater-Builder@ mailto:Repeater-Builder%40yahoogroups.com yahoogroups.com Subject: RE: [Repeater-Builder] duplexer isolation and receiver noise budget John, It might be instructive to let the big-name combiner companies make proposals to solve your dilemma. Send a request for proposals to Telewave, TX-RX, and RFS/Celwave to see what they would recommend. Don't try to design it for them; just give them the frequencies, power outputs, receive sensitivities, feedline type and length, and make/model antenna, and let them come up with their own plans. I think you will be surprised that more than one solution may do the job. My gut feeling is that your requirement to use just one antenna may be a killer, cost-wise. I can think of several
[Repeater-Builder] GLB 400b Channelizer Schematic/Manual
Can anyone point me to where I can find a manual for the GLB400b Channelizer? I have an operators manual but there is no schematic and as it turns out there are some un-attached wires floating aroud inside and I need to find out where they go toAny help would be great.. I looked on the repeater builder web site but no luck Steve NU0P
Re: [Repeater-Builder] 220MHz Repeater Amp.
Crescend makes ;possibly the best out there, but I don't know if they make any that will cover the 220 ham band. On 10/7/07, Eric Lemmon [EMAIL PROTECTED] wrote: Adam, Look into TPL amplifiers, at www.tpl.com 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.comRepeater-Builder%40yahoogroups.com [mailto:Repeater-Builder@yahoogroups.comRepeater-Builder%40yahoogroups.com] On Behalf Of Adam C. Feuer Sent: Sunday, October 07, 2007 3:29 PM To: repeater-builder@yahoogroups.com repeater-builder%40yahoogroups.com Subject: [Repeater-Builder] 220MHz Repeater Amp. Hello All, Looking for any suggestions other than Henry Radio or TE Systems for a 220MHz repeater amp. Preferably 5 to 10 watts in with 100 or so out. Thanks in advance! Adam N2ACF -- James Adkins, KB0NHX Vice-President Repeater Trustee Nixa Amateur Radio Club, Inc. (KC0LUN) District 1 Technical Field Engineer Troop A--Lee's Summit; Troop H--St. Joseph Missouri State Highway Patrol 504 SE Blue Parkway Lee's Summit, MO 64063 816-622-0707 ext. 235 417-840-5261 (Cell) Those saying it can't be done should stay out of the way of those doing it --Chinese proverb accepted and adhered to by the Nixa Amateur Radio Club, Inc., A 501(c)(3) organization working together with the community to enhance the robustness of Southwest Missouri Emergency Communications
[Repeater-Builder] Sinclair link
I'm sorry I forgot the link in the first post. http://my.ebay.com/ws/eBayISAPI.dll?MyeBayssPageName=STRK%3AME%3ALNLKCurrentPage=MyeBaySellingMyeBay=guest=1 Mick -- I pledge allegiance to the flag of the United States of America, and to the republic for which it stands, one nation, UNDER GOD, indivisible, with liberty and justice for all. - Never own anything you aren't willing to drill a hole in. See our web site at http://LindleyOnline.com
[Repeater-Builder] Radius M208 Service Manual
Does anyone on the group have a service manual for a Motorola Radius M208. We have one of these radios at our 10 meter receive site that needs repair. The repeater is down until I can locate a service manual for it. Dan, N9UWE
Re: [Repeater-Builder] Radius M208 Service Manual
If this is also known as a GM300, have you looked on www.repeater-builder.com? Bob M. == --- Dan [EMAIL PROTECTED] wrote: Does anyone on the group have a service manual for a Motorola Radius M208. We have one of these radios at our 10 meter receive site that needs repair. The repeater is down until I can locate a service manual for it. Dan, N9UWE Building a website is a piece of cake. Yahoo! Small Business gives you all the tools to get online. http://smallbusiness.yahoo.com/webhosting
[Repeater-Builder] micor repeater and tower
I have a micor complete system cabinet tuned on 443.400 with a pl of 107.2 I am looking to sell it. it has the Motorola cans in it. it has an astron 50 amp power supply and three 26 amp hour gel cell batteries for back up the repeater cabinet has the 12 volt power supply. it also has a arcom rc210 controller already wired in and connected. so it is ready to go just tune for your frequency and your on the air. i am please call me at 678-455-5093 if your interested in buying it i also have 7 and a half sections of rohn 25 complete with 200' guy cable, brackets to mount the guy cables to the tower, guy cable insulators, and turn buckles, a house bracket, and bolt kits for the tower the tower top section has the thrust bearing top i have an 8' mast pipe to go out of the top. again if your interested call me at 678-455-5093 these must sell buy the end of the month so give me a call see ya 73's N1IB David Schornak K2 03027 www.n1ib.com http://www.n1ib.com/ www.n1ib.com/blog/ www.n1ib.com/leather/ arf don't forget me Mis Ginger Einstein said: You see, wire telegraph is a kind of a very,very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat.
Re: [Repeater-Builder] GLB 400b Channelizer Schematic/Manual
There are several people selling reproductions of the complete manual for that unit for about $21. Bob M. == --- Steve White [EMAIL PROTECTED] wrote: Can anyone point me to where I can find a manual for the GLB400b Channelizer? I have an operators manual but there is no schematic and as it turns out there are some un-attached wires floating aroud inside and I need to find out where they go toAny help would be great.. I looked on the repeater builder web site but no luck Steve NU0P Be a better Heartthrob. Get better relationship answers from someone who knows. Yahoo! Answers - Check it out. http://answers.yahoo.com/dir/?link=listsid=396545433
