[Repeater-Builder] Looking for a bare Compa rack
Hello All, I am looking for an empty or bare Motorola Compa cabnet. Must also have doors that work. If it also looks good that would be nice. Please contact me direct off list. [EMAIL PROTECTED] or [EMAIL PROTECTED] Very best of 73, Russ, W3CH 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] Please help with a portable repeater case
I recently built a portable repeater using one of the aluminum tech tool boxes you can find at Home depot.I installed 2 Icom ICF-221 S radios,a rig runner power pole interface and a B D controller with plenty of space in between. I also installed a 3" muffin fan in the lid and four 2" round soffit vents.The fan draws air into the box from the sides and out the lid.This keeps everything real cool inside. It was easy to put the holes into the case-a 2" hole saw cut nice clean holes. The case cost 19.95 at the Depot here in Buffalo-prices may vary where you are. No room for the power supply however.I have a switching supply or a big gel cell pack to run it on. I hope this helps-Good luck! Scott KB2TRQ 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 the Yahoo! Terms of Service.
Re: [Repeater-Builder] Looking for a UHF Micor PA Deck
Larry let me check I'm sure I have one. they are in the shack outside. but its raining cats and dogs so it may be tomorrow before I can check. Lloyd Kd4HTW"[EMAIL PROTECTED]" [EMAIL PROTECTED] wrote: I just picked up a MICOR UHF Repeater that needs a PA deck. I'd like tofind a TLE171X Series (20, 45 or 75 Watt). I know the 75 watt 450-470 MHzversion is a TLE1713A, but if I have a choice of power levels, I'd preferthe 20 or 45 watt 450-470 Range amp (those are probably TLE1711A andTLE1712A versions).I also need one or two more KXN1052A UHF MICOR Transmit channel elements. LarryOriginal Message:-From: johnmichaelwelton [EMAIL PROTECTED]Date: Sun, 02 May 2004 01:39:19 -To: [EMAIL PROTECTED]Subject: [Micor] Micor PAIs there a way to use the Micor continuous duty PA with a Mitrek mobile as exciter? John, N4SJWYahoo! Groups Linksmail2web - Check your email from the web athttp://mail2web.com/ .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 the Yahoo! Terms of Service.
RE: [Repeater-Builder] Re: Mitrek Still Popular as a Repeater Project Radio?
I agree...I would say $25 is the standard price but if someone really needs one. You will need to go to $10 and $15 to sell fast and in quantity. Mitreks are good radios but the influx of cheap Delta's and Rangers (no need for crystals)has really made the market tight for crystal rigs. Rich -Original Message- From: johnmichaelwelton [mailto:[EMAIL PROTECTED] Sent: Tuesday, May 04, 2004 7:40 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Mitrek Still Popular as a Repeater Project Radio? Skipp, I'll take a few UHF units at a good price - just paid $10 for some T44 Mitreks and $15 for T83's/T81's locally here in SC. TNX , John, N4SJW --- In Repeater-Builder@yahoogroups.com, skipp025 [EMAIL PROTECTED] wrote: Was at a Private Company Sale today... looking at about 200 plus Motorola Mitreks ready for auction. Are they still popular with you folks for repeater projects? I'm trying to estimate demand and an offer each radio price. A mixed bag of UHF VHF units with mixed power levels. After this, I'll ask you the same questions about the 200 plus remote head Spectras in the next shelf down. Your turn... skipp Yahoo! Groups Links 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] Please help with a portable repeater case
Hello, Anybody know the casing that could be back packed? Thank you Chong, Kwanmeng --- Ray [EMAIL PROTECTED] wrote: Check out www. ddbunlimited.com they make inside and outdoor cabinets also make a little battery box that might work. Ray Mike Morris WA6ILQ [EMAIL PROTECTED] wrote: At 01:40 PM 5/1/04 -0500, you wrote: I am building a repeater with two TK840's. Where can I get a case so I can put a power supply , the two radios, mobile duplxer, and the controller in it so I may make it portable. Also, is there a case front to adapt the 7.1 power supply to the 5.6 kewood radios. Thank you very much. I've put a similar setup into a 20mm ammo can but it was a little tight. Check out Pelican brand equipment cases (do a google search on Pelican case)... but they aren't cheap. Also check out the roadie equipment cases that rock bands use - not sure of how to find a stocking distributor. They can be as small as a foot by a foot by 2 feet or reeeally big - some are essentially 19 rack cabinets in a box... I've seen some that were 6 feet high and on 8 inch diameter casters. I also saw a portable repeater built into a Zero brand aluminum camera case (also not cheap). Yahoo! Groups Links - Do you Yahoo!? Win a $20,000 Career Makeover at Yahoo! HotJobs __ Do You Yahoo!? Log on to Messenger with your mobile phone! http://sg.messenger.yahoo.com 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] Motorola VHF highband amp
I'm looking for a highband vhf amp, uses dual tubes in push pull. I wanna say 8623 or something such as that, solid anodes, conduction cooled. Also looking for schematic and any info to converting to 2mSSB. I heard there was a video out that showed this conversion. I'm not particular what frequency range in the vhf high band. If you have a junked amp that costs more for you to get up and going, please quote me a price. Thanks WB5UOI 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] 2m repeater IMD issue
Hi gang, Our club was allowed space (no cost) on top of a 400' tower using an existing 7/8" line. The existing UHF antenna was replaced (by the club) with a PD220-2 (142~150 range) antenna. The coverage is very good. However, on occasion when users with HTs or during a squelch tail the IMD is audible. I have added cavity filters to both the rx tx and the IMD is still there. I've looked at it with a spectrum analyzer (connected to the rx port of the duplexer) and I do see IMD when the 2m repeater's tx is on. Although, since I have the cavity filters inline the IMD is only noticeable within the passband of the rx cavity. The IMD levels are around -90dBm give or take a couple. Ok, here's the source of the IMD. At the top of this tower is also six other transmit antennas that are for 800MHz trunk systems. A total of 30 channels. The top platform is rather large but the closest 800 antenna to the 2m antenna is about5 feet. The farthest is about 12 feet. Of course, these antennas are in the same horizontal plane with the 2m antenna. Signal levels in the 800 tx band that I see at the TX or RX port of the 2m duplexer without the bandpass cavity is about -40dBm. With the cavity about -75dBm. I'm thinking of just moving the antenna about 50' down the tower (where there's no other antennas mounted) to eliminate the problem. My thinking is that with the extreme RF levels present on the top platform that I'd have to spend a fortune in filters on the 2m equipment perhaps the 800 stuff that it'd just be cheaper to move the antenna from the top. Any thoughts? I was looking into a solution using anisolator but after further research I discovered that a VHF isolator will ALLOW RF into the 2m transmitter that is in the 800MHz range. With the bandpass cavity inline there's noVHF (150~160) or UHF (450~470)signalsthat show up on the spectrum analyzer. Only the co-site 800MHz stuff is getting through the cavity. Richard 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 the Yahoo! Terms of Service.
[Repeater-Builder] Syntor X as a repeater?
Can a Syntor X, Id No. T73VBK7004BK, be converted to a 2M ham repeater. If so, how difficult is the conversion? 73, Steve KI0KY 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] Help Needed with UHF Micor PA TLE1713A
I have a UHF unified chassis Micor with the tle1713a AMP I get full pwr. out without the TLE1893B circulator in line, I have tried three different circulators. Can someone please advise me what could be wrong. Thanks Brian 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] Midland mobiles for repeater use
Can a pair of Midland Model 70 -336B mobile VHF radio be modified to operate on the 2M ham band as part of a repeater? If so, will it take more than changing crystals? Thanks, Steve KI0KY 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] 2m repeater IMD issue
Richard, That's exactly what I would do: Lower the antenna, out of the intense RF field. 73, Eric Lemmon WB6FLY Richard Sharp, KQ4KX wrote: Our club was allowed space (no cost) on top of a 400' tower using an existing 7/8 line... At the top of this tower is also six other transmit antennas that are for 800MHz trunk systems. A total of 30 channels... Of course, these antennas are in the same horizontal plane with the 2m antenna... I'm thinking of just moving the antenna about 50' down the tower (where there's no other antennas mounted) to eliminate the problem... Any thoughts? 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] Help Needed with UHF Micor PA TLE1713A
Brian, Unless you have had three defective circulators in a row, the most likely problem is that none of them were tuned to operate on your carrier frequency. Go to this site for more information: http://www.repeater-builder.com/rbtip/micoruhffilters.html 73, Eric Lemmon WB6FLY Brian wrote: I have a UHF unified chassis Micor with the TLE1713A AMP I get full pwr. out without the TLE1893B circulator in line, I have tried three different circulators. Can someone please advise me what could be wrong? 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] 2m repeater IMD issue
It would be nice to run an intermod program to see if any combination of 800 channels produced a 'hit' near the 2M input. Ssb 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] 2m repeater IMD issue
Hello Richard, Have you tried an additional cavity in the rx path? I had a similar situation with a UHF repeater and 800 mhz systems and anadditional cavity worked for my problem. Also, do you have a preamp? If so, where in the rx path is it? You should have all the filtering ahead of the preamp. 73, Bryan -Original Message-From: Richard Sharp, KQ4KX [mailto:[EMAIL PROTECTED]Sent: Tuesday, May 04, 2004 8:04 PMTo: Repeater-Builder@yahoogroups.com; [EMAIL PROTECTED]Subject: [Repeater-Builder] 2m repeater IMD issue Hi gang, Our club was allowed space (no cost) on top of a 400' tower using an existing 7/8" line. The existing UHF antenna was replaced (by the club) with a PD220-2 (142~150 range) antenna. The coverage is very good. However, on occasion when users with HTs or during a squelch tail the IMD is audible. I have added cavity filters to both the rx tx and the IMD is still there. I've looked at it with a spectrum analyzer (connected to the rx port of the duplexer) and I do see IMD when the 2m repeater's tx is on. Although, since I have the cavity filters inline the IMD is only noticeable within the passband of the rx cavity. The IMD levels are around -90dBm give or take a couple. Ok, here's the source of the IMD. At the top of this tower is also six other transmit antennas that are for 800MHz trunk systems. A total of 30 channels. The top platform is rather large but the closest 800 antenna to the 2m antenna is about5 feet. The farthest is about 12 feet. Of course, these antennas are in the same horizontal plane with the 2m antenna. Signal levels in the 800 tx band that I see at the TX or RX port of the 2m duplexer without the bandpass cavity is about -40dBm. With the cavity about -75dBm. I'm thinking of just moving the antenna about 50' down the tower (where there's no other antennas mounted) to eliminate the problem. My thinking is that with the extreme RF levels present on the top platform that I'd have to spend a fortune in filters on the 2m equipment perhaps the 800 stuff that it'd just be cheaper to move the antenna from the top. Any thoughts? I was looking into a solution using anisolator but after further research I discovered that a VHF isolator will ALLOW RF into the 2m transmitter that is in the 800MHz range. With the bandpass cavity inline there's noVHF (150~160) or UHF (450~470)signalsthat show up on the spectrum analyzer. Only the co-site 800MHz stuff is getting through the cavity. Richard 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 the Yahoo! Terms of Service.
Re: [Repeater-Builder] Please help with a portable repeater case
I recently built a portable repeater using one of the aluminum tech tool boxes you can find at Home depot.I installed 2 Icom ICF-221 S radios,a rig runner power pole interface and a B D controller with plenty of space in between. I also installed a 3 muffin fan in the lid and four 2 round soffit vents.The fan draws air into the box from the sides and out the lid.This keeps everything real cool inside. It was easy to put the holes into the case-a 2 hole saw cut nice clean holes. The case cost 19.95 at the Depot here in Buffalo-prices may vary where you are. No room for the power supply however.I have a switching supply or a big gel cell pack to run it on. I hope this helps-Good luck! Scott KB2TRQ Scott, the price interests me: could you give me an idea of the size, and a hint on WHERE to locate it at HD? Sound like it could be useful for Wifi use also. Thanks n 73 Christian D wo1v 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] For Sale: TKR-720 repeater
I have up for sale 1 Kenwood TKR-720 VHF Repeater with Decibel Products DB-4060A Duplexer. Repeater has been tested and is in known working order. Price is 1200.00 OBO For additional info pictures please email me. Thank you, Greg 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] 2m repeater IMD issue
Bryan, No, I don't have a preamp in the circuit - it would only make things WORSE. Well, when I add additional cavities it doesn't get rid of the IMD because it's being generated somewhere else. When I'm not using a cavity the IMD is all over the VHF band at about -90dBm. However, when the cavity is inline the IMD is only visible within the passband of the rx cavity. But it's still there - on channel basically. I can see carriers appear and disappear on the rx side when the tx is on. I'm thinking that maybe the IMD is being generated on the tower somewhere. All is the same when I have a bandpass cavity on the tx side too. Man, the 800 signals are HUGE up there! All the 800 antennas are the Celwave "Penetrator" antennas. You know, the ones that are 23ft tall and8 inches diameter, 12 - 15dB gain. Richard -Original Message-From: [EMAIL PROTECTED] Hello Richard, Have you tried an additional cavity in the rx path? I had a similar situation with a UHF repeater and 800 mhz systems and anadditional cavity worked for my problem. Also, do you have a preamp? If so, where in the rx path is it? You should have all the filtering ahead of the preamp. 73, Bryan 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 the Yahoo! Terms of Service.
Re: [Repeater-Builder] Motorola VHF highband amp
I have one of those in use here. It uses 8560's. Converts to 2meters easily and biased for linear op. 10 watts drive is producing 400 watts out. Tom SaundersComm Tech, City of SeattleAmateur Radio Station N7OEP206.384.1604[EMAIL PROTECTED] 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 the Yahoo! Terms of Service.
Re: [Repeater-Builder] 2m repeater IMD issue
Richard, You said that the IMD is only there when YOUR TX in on. If this is the case you may need an Isolator for your TX. I had a site that was getting eat alive with IMD at 150 MHz only when the TX was on. Found out that the IMD was being generated in the transmitter. Put an isolator on the thing and no more IMD. Just a thought 8-) Charles Miller - Original Message - [snip] I can see carriers appear and disappear on the rx side when the tx is on. [snip] 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] For Sale: TKR-720 repeater
What frequency is it currently on ??? - Original Message - From: krantzfamily [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Tuesday, May 04, 2004 8:48 PM Subject: [Repeater-Builder] For Sale: TKR-720 repeater I have up for sale 1 Kenwood TKR-720 VHF Repeater with Decibel Products DB-4060A Duplexer. Repeater has been tested and is in known working order. Price is 1200.00 OBO For additional info pictures please email me. Thank you, Greg Yahoo! Groups Links 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] ARRL BOOK ON INTERNET LINKING
ARRL BOOK ON INTERNET LINKING VoIP: Internet Linking for Radio Amateurs -- by Jonathan Taylor, K1RFD Growing numbers of hams are using VoIP, or Voice Over Internet Protocol, in combination with their radios for long-distance communication spanning hundreds or thousands of miles. They're using the Internet as the relay between their base stations, handhelds and mobile transceivers. This is a guide to the four primary VoIP systems used by hams: EchoLink, IRLP, eQSO and WIRES-II. The book is designed for beginners who need information on how to set up and use these systems, but it also provides plenty of technical meat for those who want to dig deeper and explore how the systems actually work. Contents: Connecting The World Using A VoIP Link Conference Servers, Reflectors and Nets Other Linking Systems Setting Up Your Own Node Digital Audio and the Internet Under The Hood: Echolink Under The Hood: IRLP Legal Issues In Linking Web Resources Glossary This may be the first book ever written about ham radio applications of VoIP! Author Jonathan Taylor, K1RFD, is the creator of EchoLink and one of the top experts in Amateur Radio Voice Over Internet Protocol. He is a member of the American Radio Relay League. First edition, © 2004, The American Radio Relay League, Inc. (ISBN: 0-87259-926-4) #9264 -- $17.95 Now Shipping! Add to shopping basket73 Ian G3ZHI http://www.qsl.net/g3zhi - many ham radio links http://www.ukirlp.co.uk G4NJI IRLP 5200 Echolink 135909 Rotherham simplex 145.2875mhz GB3XN IRLP 5708 Echolink 153126 Langold 430.925 Mhz Ian Abel G3ZHI 52 Hollytree Ave Maltby Rotherham Yorkshire S66 8DY Tel: 01709 799911 Mobile 0783 338 0578 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] For Sale: TKR-720 repeater
Hello My internet connection disconnected when I sent my original reply -- just figured I should let you know in case you did get my first reply. The repeater is currently on 145.250 And the range is 136-150 Thanks, Greg __ Do you Yahoo!? Win a $20,000 Career Makeover at Yahoo! HotJobs http://hotjobs.sweepstakes.yahoo.com/careermakeover 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] Help Needed with UHF Micor PA TLE1713A
At 08:45 PM 5/4/04 +, you wrote: I have a UHF unified chassis Micor with the tle1713a AMP I get full pwr. out without the TLE1893B circulator in line, I have tried three different circulators. Can someone please advise me what could be wrong. Thanks Brian Tune the circulator. http://www.repeater-builder.com/rbtip/micoruhffilters.html Mike WA6ILQ 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] Please help with a portable repeater case
Christian, there is a picture of my Aluminum case at: http://mywebpages.comcast.net/alallum/Portable_Ham_Radio_Station.html I found mine in the Tool's Department. Al, N8ARO The case cost 19.95 at the Depot here in Buffalo-prices may vary where you are. No room for the power supply however.I have a switching supply or a big gel cell pack to run it on. I hope this helps-Good luck! Scott KB2TRQ Scott, the price interests me: could you give me an idea of the size, and a hint on WHERE to locate it at HD? Sound like it could be useful for Wifi use also. Thanks n 73 Christian D 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] 2m repeater IMD issue
I am suprised 800 will show passing thru in highband cavities, I would think moving down one rack is the smartest thing to try, as you noted it will be a low cost trial. Richard Sharp, KQ4KX wrote: Hi gang, Our club was allowed space (no cost) on top of a 400' tower using an existing 7/8 line. The existing UHF antenna was replaced (by the club) with a PD220-2 (142~150 range) antenna. The coverage is very good. However, on occasion when users with HTs or during a squelch tail the IMD is audible. I have added cavity filters to both the rx tx and the IMD is still there. I've looked at it with a spectrum analyzer (connected to the rx port of the duplexer) and I do see IMD when the 2m repeater's tx is on. Although, since I have the cavity filters inline the IMD is only noticeable within the passband of the rx cavity. The IMD levels are around -90dBm give or take a couple. Ok, here's the source of the IMD. At the top of this tower is also six other transmit antennas that are for 800MHz trunk systems. A total of 30 channels. The top platform is rather large but the closest 800 antenna to the 2m antenna is about 5 feet. The farthest is about 12 feet. Of course, these antennas are in the same horizontal plane with the 2m antenna. Signal levels in the 800 tx band that I see at the TX or RX port of the 2m duplexer without the bandpass cavity is about -40dBm. With the cavity about -75dBm. I'm thinking of just moving the antenna about 50' down the tower (where there's no other antennas mounted) to eliminate the problem. My thinking is that with the extreme RF levels present on the top platform that I'd have to spend a fortune in filters on the 2m equipment perhaps the 800 stuff that it'd just be cheaper to move the antenna from the top. Any thoughts? I was looking into a solution using an isolator but after further research I discovered that a VHF isolator will ALLOW RF into the 2m transmitter that is in the 800MHz range. With the bandpass cavity inline there's no VHF (150~160) or UHF (450~470) signals that show up on the spectrum analyzer. Only the co-site 800MHz stuff is getting through the cavity. Richard -- 73...Clark Beckman N8PZD 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] 2m repeater IMD issue
Richard, Have you tried installing a low pass filter between your 2 Mtr duplexer and the antenna feed line? I am talking about the large low pass filters that were found in the old VHF Motorola base stations that were about 1 inch in diameter and about 14 inches long. I have a similar situation where my 2 mtr antenna is also at the same elevation as numerous other 800 Mhz repeater antennas and the addition of a low pass filter in my 2 mtr repeater feed line cured the problem like you describe. The low pass filter reduces the 800 mhz energy an additional 60 db or so to help isolate your 2 mtr repeater from the 800 mhz repeaters. I also have a dual isolator on the output of my transmitter before it goes into my 6 cavity celwave BpBr 2 mtr duplexer. You will probably need both the low pass filter in your feed line and dual isolator on your transmitter to solve this kind of problem. Your other solution will be to move your antenna out of the other antennas main RF field. John, K7JL Message: 17 Date: Tue, 4 May 2004 20:03:48 -0400 From: Richard Sharp, KQ4KX [EMAIL PROTECTED] Subject: 2m repeater IMD issue Hi gang, Our club was allowed space (no cost) on top of a 400' tower using an existing 7/8 line. The existing UHF antenna was replaced (by the club) with a PD220-2 (142~150 range) antenna. The coverage is very good. However, on occasion when users with HTs or during a squelch tail the IMD is audible. I have added cavity filters to both the rx tx and the IMD is still there. I've looked at it with a spectrum analyzer (connected to the rx port of the duplexer) and I do see IMD when the 2m repeater's tx is on. Although, since I have the cavity filters inline the IMD is only noticeable within the passband of the rx cavity. The IMD levels are around -90dBm give or take a couple. Ok, here's the source of the IMD. At the top of this tower is also six other transmit antennas that are for 800MHz trunk systems. A total of 30 channels. The top platform is rather large but the closest 800 antenna to the 2m antenna is about 5 feet. The farthest is about 12 feet. Of course, these antennas are in the same horizontal plane with the 2m antenna. Signal levels in the 800 tx band that I see at the TX or RX port of the 2m duplexer without the bandpass cavity is about -40dBm. With the cavity about -75dBm. I'm thinking of just moving the antenna about 50' down the tower (where there's no other antennas mounted) to eliminate the problem. My thinking is that with the extreme RF levels present on the top platform that I'd have to spend a fortune in filters on the 2m equipment perhaps the 800 stuff that it'd just be cheaper to move the antenna from the top. Any thoughts? I was looking into a solution using an isolator but after further research I discovered that a VHF isolator will ALLOW RF into the 2m transmitter that is in the 800MHz range. With the bandpass cavity inline there's no VHF (150~160) or UHF (450~470) signals that show up on the spectrum analyzer. Only the co-site 800MHz stuff is getting through the cavity. Richard 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] 2m repeater IMD issue
Well, I considered that too. However, after further study of isolators (and discussing my situation with a manufacturer of isolators) I discovered that a VHF isolator will not stop signals in the 800MHz range from passing through it. An isolator should work great if I was dealing with several VHF transmitters at the same level on the tower. I'm wondering if the IMD is being generated somewhere on the tower, antenna(s), etc.? A bandpass cavity on the tx drops the 800MHz signal levels (as seen at the tx port) from -40dBm to -75dBm. I would think levels of -75dBm shouldn't be a problem for the 2m tx? The harmonic filter in the tx should drop the -75 to nearly nothing - right? That's why I'm thinking perhaps the IMD is being generated somewhere else. Although, it does only occur when the 2m tx is on. tnx Richard -Original Message- From: Charles Miller Richard, You said that the IMD is only there when YOUR TX in on. If this is the case you may need an Isolator for your TX. I had a site that was getting eat alive with IMD at 150 MHz only when the TX was on. Found out that the IMD was being generated in the transmitter. Put an isolator on the thing and no more IMD. Just a thought 8-) Charles Miller - Original Message - [snip] I can see carriers appear and disappear on the rx side when the tx is on. [snip] 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] 2m repeater IMD issue
Proper engineering also requires a Low Pass filter when installing an isolator, this will restrict any incoming frequencies above your operating frequency...although this is not the reason for the low pass filter...it is there to protect you from radiating any mixes at higher frequencies. Gregg R. Lengling, W9DHI, Retired Administrator http://www.milwaukeehdtv.org K2/100 S#3075 KX1 S# 57 Politics is the art of appearing candid and completely open, while concealing as much as possible. -States: The Bene Gesserit View -Original Message- From: Richard Sharp, KQ4KX [mailto:[EMAIL PROTECTED] Sent: Wednesday, May 05, 2004 9:35 AM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] 2m repeater IMD issue Well, I considered that too. However, after further study of isolators (and discussing my situation with a manufacturer of isolators) I discovered that a VHF isolator will not stop signals in the 800MHz range from passing through it. An isolator should work great if I was dealing with several VHF transmitters at the same level on the tower. I'm wondering if the IMD is being generated somewhere on the tower, antenna(s), etc.? A bandpass cavity on the tx drops the 800MHz signal levels (as seen at the tx port) from -40dBm to -75dBm. I would think levels of -75dBm shouldn't be a problem for the 2m tx? The harmonic filter in the tx should drop the -75 to nearly nothing - right? That's why I'm thinking perhaps the IMD is being generated somewhere else. Although, it does only occur when the 2m tx is on. tnx Richard -Original Message- From: Charles Miller Richard, You said that the IMD is only there when YOUR TX in on. If this is the case you may need an Isolator for your TX. I had a site that was getting eat alive with IMD at 150 MHz only when the TX was on. Found out that the IMD was being generated in the transmitter. Put an isolator on the thing and no more IMD. Just a thought 8-) Charles Miller - Original Message - [snip] I can see carriers appear and disappear on the rx side when the tx is on. [snip] Yahoo! Groups Links 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] 2m repeater IMD issue
At 10:35 AM 5/5/2004 -0400, you wrote: Well, I considered that too. However, after further study of isolators (and discussing my situation with a manufacturer of isolators) I discovered that a VHF isolator will not stop signals in the 800MHz range from passing through it. An isolator should work great if I was dealing with several VHF transmitters at the same level on the tower. ---What bothers me here about using a circulator is that you say it only occurs when your TX is active. This doesn't sound like IM to me, as that would occur regardless of whether the tx was active or not (IM is produced when external RF comes down the TX line and mixes in the PA stages. This does NOT require that the PA actually be making power). It sounds more like a classic case of mixing. Have you run all the freqs involved to see where the possibles might be? Ken -- President and CTO - Arcom Communications Makers of state-of-the-art repeater controllers and accessories. http://www.ah6le.net/arcom/index.html Be sure to see our products at this year's Dayton Hamvention! Repeater Builders spaces 707 through 710 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] 2m repeater IMD issue
Maybe I'm taking to simple of a view, but could this be some sort of harmonic? However, if my math is correct (and it usually isn't... :-p ) that would be about a 4th order harmonic, I think. (If that's even possible.) Or am I all wet? Mark - N9WYS -Original Message- From: Richard Sharp, KQ4KX [mailto:[EMAIL PROTECTED] Sent: Wednesday, May 05, 2004 9:35 AM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] 2m repeater IMD issue Well, I considered that too. However, after further study of isolators (and discussing my situation with a manufacturer of isolators) I discovered that a VHF isolator will not stop signals in the 800MHz range from passing through it. An isolator should work great if I was dealing with several VHF transmitters at the same level on the tower. I'm wondering if the IMD is being generated somewhere on the tower, antenna(s), etc.? A bandpass cavity on the tx drops the 800MHz signal levels (as seen at the tx port) from -40dBm to -75dBm. I would think levels of -75dBm shouldn't be a problem for the 2m tx? The harmonic filter in the tx should drop the -75 to nearly nothing - right? That's why I'm thinking perhaps the IMD is being generated somewhere else. Although, it does only occur when the 2m tx is on. tnx Richard -Original Message- From: Charles Miller Richard, You said that the IMD is only there when YOUR TX in on. If this is the case you may need an Isolator for your TX. I had a site that was getting eat alive with IMD at 150 MHz only when the TX was on. Found out that the IMD was being generated in the transmitter. Put an isolator on the thing and no more IMD. Just a thought 8-) Charles Miller - Original Message - [snip] I can see carriers appear and disappear on the rx side when the tx is on. [snip] Yahoo! Groups Links 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] Mitrek Still Popular as a Repeater Project Radio?
I am using a Mitrek as a 6m repeater (actually two separate for TX and RX) and it is working great. My next project is a 2M repeater from Mitreks.. Plan on finding Mitreks for around $10-$30 depending on model and channel elements being with it or not. John Clark - KI4AWK Thomasville, GA [EMAIL PROTECTED] - Original Message - From: skipp025 [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Tuesday, May 04, 2004 5:54 PM Subject: [Repeater-Builder] Mitrek Still Popular as a Repeater Project Radio? Was at a Private Company Sale today... looking at about 200 plus Motorola Mitreks ready for auction. Are they still popular with you folks for repeater projects? I'm trying to estimate demand and an offer each radio price. A mixed bag of UHF VHF units with mixed power levels. After this, I'll ask you the same questions about the 200 plus remote head Spectras in the next shelf down. Your turn... skipp Yahoo! Groups Links 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] 2m repeater IMD issue
-Original Message- From: Ken Arck ---What bothers me here about using a circulator is that you say it only occurs when your TX is active. This doesn't sound like IM to me, as that would occur regardless of whether the tx was active or not (IM is produced when external RF comes down the TX line and mixes in the PA stages. This does NOT require that the PA actually be making power). Good point. Yes, it only occurs when the 2m repeaters tx is on. Basically, what I see on the spectrum analyzer (connected to the rx port of the duplexer) is several signals coming and going within the passband of the rx cavity (+/- 300kHz approx). I can tune the analyzer to a specific carrier and hear either voice traffic or control channel. All of these signals are around -90dBm at the rx port. As soon as the 2m transmitter is turned off the carriers on the rx port disappear. It sounds more like a classic case of mixing. Have you run all the freqs involved to see where the possibles might be? At this point no. However, I'm in the process of obtaining all of the 800 freqs to do a calc. 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: 2m repeater IMD issue
I've seen some of the other posts. You should be running a dual port circulator in addition to the proper duplexer. You mention the 7/8 line is used. If you remove the connector from any end and the line is not shinny, clean the oxide off with a brass brush and replace the connector back on the cable. If the oxide color is really dark, you have moisture leakage in the cable and that's really bad news. If the PD220-2 antenna is over 10 years old, consider trying a swap out. I have replaced a number of aged PD antennas, which (along with station masters) can become IMD generators when placed in modest proximity to other antennas (and metal objects). You can measure the system desense of the terminated feed, which will provide additional clues. You should try for min 1/4 wave spacing (at vhf) from the 800Mhz antennas, where possible. cheers skipp www.radiowrench.com Richard Sharp, KQ4KX [EMAIL PROTECTED] wrote: Hi gang, Our club was allowed space (no cost) on top of a 400' tower using an existing 7/8 line. The existing UHF antenna was replaced (by the club) with a PD220-2 (142~150 range) antenna. The coverage is very good. However, on occasion when users with HTs or during a squelch tail the IMD is audible. I have added cavity filters to both the rx tx and the IMD is still there. I've looked at it with a spectrum analyzer (connected to the rx port of the duplexer) and I do see IMD when the 2m repeater's tx is on. Although, since I have the cavity filters inline the IMD is only noticeable within the passband of the rx cavity. The IMD levels are around -90dBm give or take a couple. Ok, here's the source of the IMD. At the top of this tower is also six other transmit antennas that are for 800MHz trunk systems. A total of 30 channels. The top platform is rather large but the closest 800 antenna to the 2m antenna is about 5 feet. The farthest is about 12 feet. Of course, these antennas are in the same horizontal plane with the 2m antenna. Signal levels in the 800 tx band that I see at the TX or RX port of the 2m duplexer without the bandpass cavity is about -40dBm. With the cavity about -75dBm. I'm thinking of just moving the antenna about 50' down the tower (where there's no other antennas mounted) to eliminate the problem. My thinking is that with the extreme RF levels present on the top platform that I'd have to spend a fortune in filters on the 2m equipment perhaps the 800 stuff that it'd just be cheaper to move the antenna from the top. Any thoughts? I was looking into a solution using an isolator but after further research I discovered that a VHF isolator will ALLOW RF into the 2m transmitter that is in the 800MHz range. With the bandpass cavity inline there's no VHF (150~160) or UHF (450~470) signals that show up on the spectrum analyzer. Only the co-site 800MHz stuff is getting through the cavity. Richard 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] 2m repeater IMD issue
This may not exactly fit the circumstances of the current thread. However... I was getting 800 MHz trunking interference on my 447.200 repeater receiver some years ago. I was using a WP 678- R2 duplexer and a Hamtronics LNG-450 preamp on an Exec II. The thing was, there were no 800 MHz station transmitters within five miles of the repeater site. Anyway, it seems that enough of the 800 MHz signals made it through the duplexer pass cavities to cause mixing in the preamp. In the end, the Exec II was really sensitive enough standing alone. I also once knew a fellow who used an LNG-450 on one of his MASTR Pro 460 MHz community repeaters. He had interference from a co-located two-meter repeater. In the end, the ham repeater had to go away. For him, that was more economical from both a time and expense standpoint than solving the problem otherwise. The bottom line is.. Where preamps are concerned.. Caveat Emptor! Steve, AA5SG - Original Message - From: Richard Sharp, KQ4KX [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Wednesday, May 05, 2004 10:01 AM Subject: RE: [Repeater-Builder] 2m repeater IMD issue -Original Message- From: Ken Arck ---What bothers me here about using a circulator is that you say it only occurs when your TX is active. This doesn't sound like IM to me, as that would occur regardless of whether the tx was active or not (IM is produced when external RF comes down the TX line and mixes in the PA stages. This does NOT require that the PA actually be making power). Good point. Yes, it only occurs when the 2m repeaters tx is on. Basically, what I see on the spectrum analyzer (connected to the rx port of the duplexer) is several signals coming and going within the passband of the rx cavity (+/- 300kHz approx). I can tune the analyzer to a specific carrier and hear either voice traffic or control channel. All of these signals are around -90dBm at the rx port. As soon as the 2m transmitter is turned off the carriers on the rx port disappear. It sounds more like a classic case of mixing. Have you run all the freqs involved to see where the possibles might be? At this point no. However, I'm in the process of obtaining all of the 800 freqs to do a calc. Yahoo! Groups Links 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] Re: 2m repeater IMD issue
-Original Message- From: skipp025 I've seen some of the other posts. You should be running a dual port circulator in addition to the proper duplexer. Well, I don't necessarily disagree with using an isolator/harmonic filter. However, the isolator will not keep 800MHz signals from getting to the transmitter of the 2m repeater. I'm sure the harmonic filter may reduce the 800 levels some but the isolator isn't going to stop it. Of course, an isolator will keep other VHF signals from getting back through it but I don't have any VHF signals that are a problem. The duplexer is a new TX/RX 4 can vari-notch. I've added bandpass cavities on the rx tx side between the duplexer repeater. You mention the 7/8 line is used. If you remove the connector from any end and the line is not shinny, clean the oxide off with a brass brush and replace the connector back on the cable. If the oxide color is really dark, you have moisture leakage in the cable and that's really bad news. I'd don't know exactly how old it is but it is in good shape according to the tower crew. It was previously used by a law enforcement agency before they switched to the 800 system. If the PD220-2 antenna is over 10 years old, consider trying a swap out. I have replaced a number of aged PD antennas, which (along with station masters) can become IMD generators when placed in modest proximity to other antennas (and metal objects). I purchased the PD220-2 antenna new late last year. It was drop shipped directly from Celwave. I installed a new polyphaser at the entry port but I haven't tried taking it out of the circuit to see if it's contributing to the problem. Has anyone seen a polyphaser do bad things? You can measure the system desense of the terminated feed, which will provide additional clues. Good idea. You should try for min 1/4 wave spacing (at vhf) from the 800Mhz antennas, where possible. The closest antenna to the PD220 is about 4 to 5 feet away. cheers skipp www.radiowrench.com 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] 2m repeater IMD issue
Duplexers with one loop in UHF do not do much at 800 Mhz - have 4 repeaters with WP678's on 2 antennas, abt 10 ft from 800 SMR transmit antenna - horizontal - ended up placing decibel band pass 2 loop cans in front of each receiver - to keep 800 from really desensensing the 460 recs. Uniden 460 LTR system and Johnson 800 VX trunking systems on the Alico Building in Waco, TX. Ssb 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] 2m repeater IMD issue
At 11:52 AM 5/5/2004 -0500, you wrote: Duplexers with one loop in UHF do not do much at 800 Mhz - ---He was talking about VHF circulators not being effective at preventing 800 Mhz energy from passing back down the TX line? I've never heard of this before. Ken -- President and CTO - Arcom Communications Makers of state-of-the-art repeater controllers and accessories. http://www.ah6le.net/arcom/index.html Be sure to see our products at this year's Dayton Hamvention! Repeater Builders spaces 707 through 710 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] Re: 2m repeater IMD issue
At 12:43 PM 5/5/2004 -0400, you wrote: However, the isolator will not keep 800MHz signals from getting to the transmitter of the 2m repeater. ??? Ken -- President and CTO - Arcom Communications Makers of state-of-the-art repeater controllers and accessories. http://www.ah6le.net/arcom/index.html Be sure to see our products at this year's Dayton Hamvention! Repeater Builders spaces 707 through 710 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] 2m repeater IMD issue
Take a tracking generator and sweep a Wacom 678 duplexer and look beyond 440 / 450 on up to 600 and beyond. If memory is correct a single cavity will have less than 10 db attenuation at 800. Ssb 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] 2m repeater IMD issue
At 12:34 PM 5/5/2004 -0500, you wrote: Take a tracking generator and sweep a Wacom 678 duplexer and look beyond 440 / 450 on up to 600 and beyond. If memory is correct a single cavity will have less than 10 db attenuation at 800. ---I said CIRCULATOR, not DUPLEXER :-) Ken -- President and CTO - Arcom Communications Makers of state-of-the-art repeater controllers and accessories. http://www.ah6le.net/arcom/index.html Be sure to see our products at this year's Dayton Hamvention! Repeater Builders spaces 707 through 710 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/
[Repeater-Builder] Query - Maggiore Hi Pro EV1 Exciter CTCSS
Has anyone on the list successfully connected a ComSpec or other CTCSS encoder to one of these exciters? I don't expect I will have any difficulty with it, but just wanted to avoid reinventing the wheel. This is part of a Hi Pro R1 repeater. Thanks! Steve, AA5SG 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] Re: 2m repeater IMD issue
At 5/5/2004 08:56 AM, you wrote: I've seen some of the other posts. You should be running a dual port circulator in addition to the proper duplexer. As Richard has correctly indicated in his previous posts, an isolator will not have an effect on his IMD problem. Having said that, however, it still would be a good idea to put a single-port isolator on the TX. The reason is so that the RFPA sees 50 ohms over a broad bandwidth. Some RFPAs (like the high-power GEs) don't like to see pure reactance anywhere within their operating range, even if it's not on the frequency where power is being generated. My guess is that the IMD is in fact being generated on the tower. 95% of the on-site mixes I discover these days are found in tower joints, electrical conduit, air conditioning ducts, etc. One just popped up on my input after changing a 420 link channel (2 watt TX 100 ft. below main RX antenna). I didn't even bother to look for the sources; I just decided to swap link channels again. Bob NO6B 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] Re: 2m repeater IMD issue
Skipp has some good ideas, here's another one. Try adding an LPF between your duplexer and hard line. A harmonic filter out of a high band Micor or something similiar. This shouldn't affect your signal at 2M much, but it should drop the 800 MHz stuff down 80 dB or more, depending on filter. If there is no change in IM, then it is probably occuring at the antenna or tower. A cracked solder joint in your antenna, or one of the 800M antennas could be causing the problem. This could act as a mixing point when your 2M TX is on. Of course anything in close proximity to your TX antenna could be causing this as well, if it is acting as a junction. Joe --- Richard Sharp, KQ4KX [EMAIL PROTECTED] wrote: -Original Message- From: skipp025 I've seen some of the other posts. You should be running a dual port circulator in addition to the proper duplexer. Well, I don't necessarily disagree with using an isolator/harmonic filter. However, the isolator will not keep 800MHz signals from getting to the transmitter of the 2m repeater. I'm sure the harmonic filter may reduce the 800 levels some but the isolator isn't going to stop it. Of course, an isolator will keep other VHF signals from getting back through it but I don't have any VHF signals that are a problem. The duplexer is a new TX/RX 4 can vari-notch. I've added bandpass cavities on the rx tx side between the duplexer repeater. You mention the 7/8 line is used. If you remove the connector from any end and the line is not shinny, clean the oxide off with a brass brush and replace the connector back on the cable. If the oxide color is really dark, you have moisture leakage in the cable and that's really bad news. I'd don't know exactly how old it is but it is in good shape according to the tower crew. It was previously used by a law enforcement agency before they switched to the 800 system. If the PD220-2 antenna is over 10 years old, consider trying a swap out. I have replaced a number of aged PD antennas, which (along with station masters) can become IMD generators when placed in modest proximity to other antennas (and metal objects). I purchased the PD220-2 antenna new late last year. It was drop shipped directly from Celwave. I installed a new polyphaser at the entry port but I haven't tried taking it out of the circuit to see if it's contributing to the problem. Has anyone seen a polyphaser do bad things? You can measure the system desense of the terminated feed, which will provide additional clues. Good idea. You should try for min 1/4 wave spacing (at vhf) from the 800Mhz antennas, where possible. The closest antenna to the PD220 is about 4 to 5 feet away. cheers skipp www.radiowrench.com __ Do you Yahoo!? Win a $20,000 Career Makeover at Yahoo! HotJobs http://hotjobs.sweepstakes.yahoo.com/careermakeover 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: Help Needed with UHF Micor PA TLE1713A
--- In Repeater-Builder@yahoogroups.com, Mike Morris WA6ILQ [EMAIL PROTECTED] wrote: At 08:45 PM 5/4/04 +, you wrote: I have a UHF unified chassis Micor with the tle1713a AMP I get full pwr. out without the TLE1893B circulator in line, I have tried three different circulators. Can someone please advise me what could be wrong. Thanks Brian Tune the circulator. http://www.repeater-builder.com/rbtip/micoruhffilters.html Mike WA6ILQ I fiquired it out, The repeaters I have were 2watt versions and I had to bypass the anttenuator, Thanks for the info. It helps when You have the Manual, Which I did not have until today. 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/
