Re: [Repeater-Builder] Re: Duplexer parts
Sorry Skipp, never got that request, sometimes I think not all the emails to this group end up getting forwarded to me. If you've followed the thread you know I did order one that is not quite exact but should work. Thanks again everyone for your help. Gary - K7NEY On 4/17/2010 5:52 PM, skipp025 wrote: Joe k1ike_m...@... wrote: I don't know if this was suggested, but you can buy a cap of larger value that physically fits the area and then remove a plate/stator or two to get the proper value. Removing a plate and/or stator is a trick from way back in ham time when people scrounged parts and made them work. 73, Joe, K1ike I suggested the guy Email me a few well lighted pictures of the bad cap and I would have probably sent him one or told him of places I know where he could still buy them. Oh well... times up. s. ps: Seems most Amateur Photographers suffer from lack of decent lighting disease in their pictures so I always ask folks to kick the photon level up a bit when taking and submitting images.
Re: [Repeater-Builder] Re: Duplexer parts
Thanks, I sent them an email and they said they haven't sold that capacitor in 25 years and all spec sheets, etc are all gone. Was worth a try though. I'll keep looking Gary On 4/15/2010 4:28 PM, ac6vj wrote: Gary, Try Viking Technologies LTD. at www.cardwellcondenser.com they have a very large selection of Johnson, series 167 capacitors and will be able to give you the exact specifications on the broken one that you have. Gregory AC6VJ --- In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com, Gary Hoff k7ney...@... wrote: I already found that one, thanks anyway, the 167-205 is close but not enough plates, mine has 6 rotor and 6 stator. Physical size is right though, maybe this cap was made by Johnson also since the numbers are close. Gary On 4/15/2010 1:59 PM, DCFluX wrote: http://www.surplussales.com/Variables/ButterflyCapacitors/ButCap1.html http://www.surplussales.com/Variables/ButterflyCapacitors/ButCap1.html http://www.surplussales.com/Variables/ButterflyCapacitors/ButCap1.html http://www.surplussales.com/Variables/ButterflyCapacitors/ButCap1.html (CAV) 167-205-71 sounds close to it. On Thu, Apr 15, 2010 at 11:59 AM, Gary Hoff k7ney...@... mailto:k7ney123%40q.com wrote: I have an old Phelps Dodge VHF Duplexer that has a frozen air variable. The Duplexer is a part# 499-509 and covers 144-174. The air variable in question is stamped 167-202 and is split stator about 1 3/8 square. Anybody know where I might find a suitable replacement, I haven't had any luck where I've been looking. Gary K7NEY Yahoo! Groups Links
Re: [Repeater-Builder] Re: Duplexer parts
I don't think I could make one. I've seen rotors and stators available you can assemble yourself but they are quite a bit larger and wouldn't fit in the box. I think I've found one that I can make work and ordered it. It's not exact, but it'll fit in the spot and should function OK. Thanks to all who responded to my query. There were a lot of good ideas and they are all appreciated. Gary - K7ney On 4/16/2010 9:58 PM, Barry wrote: If all else fails it should be simple to work out the requirements and make one requires some manual skill and patience though To: Repeater-Builder@yahoogroups.com From: k7ney...@q.com Date: Fri, 16 Apr 2010 06:49:25 -0600 Subject: Re: [Repeater-Builder] Re: Duplexer parts Thanks, I sent them an email and they said they haven't sold that capacitor in 25 years and all spec sheets, etc are all gone. Was worth a try though. I'll keep looking Gary On 4/15/2010 4:28 PM, ac6vj wrote: Gary, Try Viking Technologies LTD. at www.cardwellcondens http://www.cardwellcondenser.com they have a very large selection of Johnson, series 167 capacitors and will be able to give you the exact specifications on the broken one that you have. Gregory AC6VJ --- In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder@yahoogroups.com, Gary Hoff k7ney...@... wrote: I already found that one, thanks anyway, the 167-205 is close but not enough plates, mine has 6 rotor and 6 stator. Physical size is right though, maybe this cap was made by Johnson also since the numbers are close. Gary On 4/15/2010 1:59 PM, DCFluX wrote: http://www.surplussales.com/Variables/ButterflyCapacitors/ButCap1.html http://www.surplussales.com/Variables/ButterflyCapacitors/ButCap1.html http://www.surplussales.com/Variables/ButterflyCapacitors/ButCap1.html http://www.surplussales.com/Variables/ButterflyCapacitors/ButCap1.html (CAV) 167-205-71 sounds close to it. On Thu, Apr 15, 2010 at 11:59 AM, Gary Hoff k7ney...@... mailto:k7ney123%40q.com wrote: I have an old Phelps Dodge VHF Duplexer that has a frozen air variable. The Duplexer is a part# 499-509 and covers 144-174. The air variable in question is stamped 167-202 and is split stator about 1 3/8 square. Anybody know where I might find a suitable replacement, I haven't had any luck where I've been looking. Gary K7NEY Yahoo! Groups Links Looking for a hot date? View photos of singles in your area! http://clk.atdmt.com/NMN/go/150855801/direct/01/
[Repeater-Builder] Duplexer parts
I have an old Phelps Dodge VHF Duplexer that has a frozen air variable. The Duplexer is a part# 499-509 and covers 144-174. The air variable in question is stamped 167-202 and is split stator about 1 3/8 square. Anybody know where I might find a suitable replacement, I haven't had any luck where I've been looking. Gary K7NEY
Re: [Repeater-Builder] Duplexer parts
I already found that one, thanks anyway, the 167-205 is close but not enough plates, mine has 6 rotor and 6 stator. Physical size is right though, maybe this cap was made by Johnson also since the numbers are close. Gary On 4/15/2010 1:59 PM, DCFluX wrote: http://www.surplussales.com/Variables/ButterflyCapacitors/ButCap1.html http://www.surplussales.com/Variables/ButterflyCapacitors/ButCap1.html (CAV) 167-205-71 sounds close to it. On Thu, Apr 15, 2010 at 11:59 AM, Gary Hoff k7ney...@q.com mailto:k7ney123%40q.com wrote: I have an old Phelps Dodge VHF Duplexer that has a frozen air variable. The Duplexer is a part# 499-509 and covers 144-174. The air variable in question is stamped 167-202 and is split stator about 1 3/8 square. Anybody know where I might find a suitable replacement, I haven't had any luck where I've been looking. Gary K7NEY Yahoo! Groups Links
Re: [Repeater-Builder] DB-4072 duplexers
I tuned one at one time on 447.05/442.05 and it worked well. Don't remember the rejection numbers though. Gary - K7NEY On 2/5/2010 9:52 PM, James Adkins wrote: Wondering if anyone knows if the 6-cavity set of DB-4072's made for 450-470 MHz will go down to 444.425 MHz / 449.425 MHz? I know the specs say only down to 450, looking for anyone that's tuned these in the real world and how low you've tuned them. Thanks, -- James Adkins, KB0NHX
Re: [Repeater-Builder] IFR 1600S
I have a 1600S, have had it now for about 3 years. No trouble at all. I Love it.. The operators manual is available on the net in a PDF, however I got mine from the company I purchased the Monitor from in printed form. It's several hundred pages. Gary - K7NEY shibukiau wrote: I have a chance to acquire an IFR 1600S and would like some users reports on their experience relative to the instruments performance and reliability to help me make my decision! Are manuals available somewhere for these units other than from IFR?? Thanks for your help!! Lloyd VE3ERQ
Re: [Repeater-Builder] Re: IFR 1600S
I sent it to Mike WA6ILQ for posting on the Repeater Builder Site, It's a really big file, youcan get it there when he gets it posted. I couldn't find it again on the internet but had a copy on my system. Gary shibukiau wrote: Thanks for the comments Gary -- much appreciated!! Could you send me the link for the operators manual?? I don't have any info on the unit so I'm sort of flying blind trying to run this unit!! Thanks again for your help!! Lloyd VE3ERQ --- In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com, Gary Hoff k7ney...@... wrote: I have a 1600S, have had it now for about 3 years. No trouble at all. I Love it.. The operators manual is available on the net in a PDF, however I got mine from the company I purchased the Monitor from in printed form. It's several hundred pages. Gary - K7NEY shibukiau wrote: I have a chance to acquire an IFR 1600S and would like some users reports on their experience relative to the instruments performance and reliability to help me make my decision! Are manuals available somewhere for these units other than from IFR?? Thanks for your help!! Lloyd VE3ERQ
Re: [Repeater-Builder] Re: wp-639 -- How far should I expect to move the invar rods?
Joe is correct, if you're going to try an tune it without the proper test equipment, you will not get it perfect. It may work, but not as well as it could. Early in my career, I was able to tune a duplexer with a couple HT's, one for xmit and one for receive, but I found I needed a step attenuator to keep from saturating the receiving HT. I was really proud of myself cause I could tune for the peak and the null by using this method. It worked, but later when I had access to the proper equipment, I checked the duplexer and found I missed the proper settings by 10 Db on one side and 15 on the other. I don't think there is anyway you'll be able to tune it by ear. Try and find someone with the proper gear, you'll be much happier in the end. Gary - K7NEY Joe wrote: Hopefully, you have only tried to tune on of the cans. If you still have a can that is tuned to the original frequency they were working (???) on, try to follow the procedure on repeater builders carefully. If you get that one working, you can try to set the rods to the same dimensions as the good one a try to tune the other ones. It is possible to get a duplexer working satisfactorily (but probably not optimally) without the proper test equipment (tracking generator, etc) but takes a lot of patience and time. I did it many years ago to a set of homebrew 220Mhz cans with an HT and an RF detector on an Oscilloscope. After several nights of tuning and graphing results I got them to work very well. If you start with a working set of cans, moving them to a new frequency is easier. It sounds like you need to hook up with someone that has a service monitor or a network analyzer. Where are you located? Maybe someone can give you a hand. 73, Joe, K1ike
Re: [Repeater-Builder] wp-639 rexolite
I have in face tuned a WP-639 and would guess for that freq swing from 146.97 to 146.88 it will be very little movement of the rod assuming the pass tuning is correct. Remember, the rexolite rod is tuning the notch and that notch is relative to the pass setting of the invar rod. It is extremely sharp and has to be moved only very slightly to find the deepest part of the notch. Tune your generator (HT) to the notch frequency (.28) and feed it through the hi-pass section of the duplexer and tune for the null. Be careful that you don't mistakenly tune the low-pass section of the duplexer to pass the high frequency because sometimes you can find a null but not the right one. I would tune it for you for nothing but I have no Idea where you are located and I'm sure there are others who would also if you would give a location so someone could respond. Gary - K7NEY hbbcara wrote: Hi again, In my first post I miswrote a thing or two and much confusion as to my question ensued. Hopefully I've written this more clearly. Thank you to all who responded to my earlier question and my apologies for wasting your time by having you answer the wrong question. I have a wp-639. I'm its at least third owner and don't know its previous history. It's got a factory sticker marked 146.97 / 37. I don't know anyone who currently has the correct equipment locally and I don't have the budget to take it to a radio shop so I've used alternate methods of tuning similar to mentioned on the repeater builder website. I've gotten it tuned to work OK with my repeater on 146.88 / 28 but I'm guessing it could be better. In tuning the pass adjustments, there was a definite sweet spot. Go a quarter or a third of a turn off of that and there was a definite difference. But I didn't find that sweet spot in tuning the reject and I wonder how wide of an adjustment it usually is. What I mean is, for example the pass tuning went from not very good to good to not as good within about one turn of the knob. In tuning the reject, should I be looking for that pattern while moving the rexolite over an inch of travel, a half-inch, two inches or ? So my question is not how to tune it but as I tune it, how much should I expect to have to move the rexolite rods to notice the not good – good – not good pattern? Or will it even be there? I suppose the question is only to those who have tuned a wp-639 for a standard 600kc split. Someone who hasn't tuned a `639 will be basing their answer on a comparison to something they have tuned, which may not be all that comparable. For the sake of brevity I won't post the method I used to tune it unless someone wants to know it. Again, thanks to those who answered earlier and thanks in advance any who answer this. rj Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * Your email settings: Individual Email | Traditional * To change settings online go to: http://groups.yahoo.com/group/Repeater-Builder/join (Yahoo! ID required) * To change settings via email: mailto:repeater-builder-dig...@yahoogroups.com mailto:repeater-builder-fullfeatu...@yahoogroups.com * To unsubscribe from this group, send an email to: repeater-builder-unsubscr...@yahoogroups.com * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: MASTR II PTT
Is this the serial port or the parallel port on the computer that you are using? The serial port I always thought met RS-232 standards which swung from positive to negative. I used to use a RS232 to TTL logic converter back in the good old days to convert the signals but it was a commercial computer, not a PC. Measure the voltage out of the computer and see what you really have. A half volt swing is not enough. Gary - K7NEY Chuck Kelsey wrote: Sounds like the transistor isn't biased on all the way. Could be the series resistor on the transistor base is too high a resistance value or the transistor choice was bad. A 2N3904 or 2N should work OK. If you really want a hard low, use a power mosfet instead of the transistor - like a 2N7000 or a VN10LP. In that case, the gate would correspond to the base connection, the Source goes to ground, and the Drain is your connection to the PTT on the radio. Chuck WB2EDV - Original Message - *From:* Vernon Densler mailto:m...@highwayusa.com *To:* Repeater-Builder@yahoogroups.com mailto:Repeater-Builder@yahoogroups.com *Sent:* Saturday, April 18, 2009 6:05 PM *Subject:* RE: [Repeater-Builder] Re: MASTR II PTT With the simple echolink interace which has a NPN transistor doing the switching the voltage across the PTT line and ground is 7v when the com port is not active and 6.5v when it’s active. So I am only getting a ½ volt drop instead of a total short to ground. Is it because the transistor can’t pull it down far enough? Will a transistor with a higher power dissipation help? Thanks, Vern
Re: [Repeater-Builder] Sinclair Q2220E
I did use one on 2 meters however never was able to get more than about 65Db Isolation. Worked OK as long as we kept the transmitter power low. Gary - K7NEY Terry wrote: Does anyone have experience using this model on 2 meters? Do they provide enough practical isolation for single antenna, 600kc split? (Sinclair Q2220E 4 Cavity VHF BpBr Repeater)
Re: [Repeater-Builder] Re: Help with intermod between repeaters.
This is one of the toughest intermod products to solve. 2 transmitters 600 kHz apart generate spurs every 600 kHz on both sides of each transmitter. When we were co-ordinating repeaters, it's one parameter we always looked at, and tried to keep nearby repeaters off of that 600 KHZ separation boundary. Are Both repeaters having problems or just yours? These signals don't even have to be generated in your equipment, I've seen them generated by stuff externally and if you look at a spectrum analyzer when both transmitters are on the air, you'll see the Christmas tree like display showing the spikes every 600 kHz decreasing with amplitude as they get farther away. Most suggestions made may help and all I can say is good luck, the only real way out of this problem may be a frequency change for one or the other machine.] Gary - K7NEY - Original Message - From: wa5luy To: Repeater-Builder@yahoogroups.com Sent: Sunday, February 15, 2009 6:15 AM Subject: [Repeater-Builder] Re: Help with intermod between repeaters. Thanks to all for your replies. Joe M wrote You need to reject the opposite TX on each repeater. Your BP filters were set wrong. You rejected the RX on the TX side - something the duplexer should be doing already. You need to install them in the repeater and reject the other TX. IOW, install a filter in the .16 repeater and notch the .36 TX. A good duplexer should do this as well, but many don't. Joe that's what I thought I did. Maybe I did not make myself clear. I put a BPBR cavity rejecting 146.76 and passing 147.36 between the repeater transmitter and the duplexer at the 147.36 repeater. This is where I was surprised that the mixing got worse. If I put the cavity in the wrong place let me know. Eric Lemmon WB6FLY wrote The first question that enters my mind is, were both Micor stations originally built as repeaters, with the extra filters and shielding plates,or are one or both base stations that have been converted to repeaters? I built our repeater. It's the 146.76 machine. It was originally a pager TX. All shielding and the lo pass TX filter is in place. I have looked at it with a spectrum analyzer and see no other signal than 146.76. I have no idea as to what the other repeater was made from. I will take a second look at their TX. The next time I go down there I plan to take a 50 watt radio and connect it to their duplexer to try to eliminate or prove their PA has a problem. The second question is, are either or both repeaters equipped with ferrite isolators? The 146.76 has no isolator. The 147.36 has a brand new, I believe Sinclair, isolator that was factory built for this frequency. The isolator has no affect on the problem although I don't think it's installed properly. I did not notice when I was there but I think it's mounted on a steel plate. Also there in no cavity between it and the duplexer. The mixing is there with or without the isolator in line. They paid big bucks thinking this would fix the problem. By the way they also replaced their antenna and feed line which may have made the mixing worse. John wrote I hate to tell you, a definite way to eliminate the problem, is a frequency change so that the output of the two transmitters are no longer not 600 khz apart. Funny that`s the first thing I told them. I am familiar with two pagers 600 khz apart and the havoc that can be raised. I plan to go back down there when I have time and let the group know what I find. Again thanks to all.
Re: [Repeater-Builder] Re: Help with intermod between repeaters.
Has nothing to do with the spacing, but with the intermod products generated by the two transmitters exactly 600 kHz apart generating spurious signals on the inputs of the receivers. Gary - K7NEY - Original Message - From: MCH To: Repeater-Builder@yahoogroups.com Sent: Sunday, February 15, 2009 12:19 PM Subject: Re: [Repeater-Builder] Re: Help with intermod between repeaters. 18 miles apart and 1.2 MHz separation? How far apart do you want to space repeaters? I know of repeaters only 210 kHz apart at the same site that work fine. Joe M. AJ wrote: When were these two repeaters coordinated? RX freq so close to the TX freq of the other repeater doesn't exactly sound like a good engineering practices, even with 18 miles between the two sites... On Sun, Feb 15, 2009 at 9:37 AM, Gary Glaenzer glaen...@verizon.net mailto:glaen...@verizon.net wrote: well said - Original Message - *From:* Gary Hoff mailto:k7ney...@q.com *To:* Repeater-Builder@yahoogroups.com mailto:Repeater-Builder@yahoogroups.com *Sent:* Sunday, February 15, 2009 10:33 AM *Subject:* Re: [Repeater-Builder] Re: Help with intermod between repeaters. */This is one of the toughest intermod products to solve. 2 transmitters/* */600 kHz apart generate spurs every 600 kHz on both sides of each/* */transmitter. When we were co-ordinating repeaters, it's one parameter/* */we always looked at, and tried to keep nearby repeaters off of that/* */600 KHZ separation boundary. Are Both repeaters having problems or just yours?/* */These signals don't even have to be generated in your equipment,/* */I've seen them generated by stuff externally and if you look at a /* */spectrum analyzer when both transmitters are on the air, you'll see/* */the Christmas tree like display showing the spikes every 600 kHz decreasing/* */with amplitude as they get farther away. Most suggestions made may/* */help and all I can say is good luck, the only real way out of this/* */problem may be a frequency change for one or the other machine.]/* */Gary - K7NEY/* - Original Message - *From:* wa5luy mailto:wa5...@cablelynx.com *To:* Repeater-Builder@yahoogroups.com mailto:Repeater-Builder@yahoogroups.com *Sent:* Sunday, February 15, 2009 6:15 AM *Subject:* [Repeater-Builder] Re: Help with intermod between repeaters. Thanks to all for your replies. Joe M wrote You need to reject the opposite TX on each repeater. Your BP filters were set wrong. You rejected the RX on the TX side - something the duplexer should be doing already. You need to install them in the repeater and reject the other TX. IOW, install a filter in the .16 repeater and notch the .36 TX. A good duplexer should do this as well, but many don't. Joe that's what I thought I did. Maybe I did not make myself clear. I put a BPBR cavity rejecting 146.76 and passing 147.36 between the repeater transmitter and the duplexer at the 147.36 repeater. This is where I was surprised that the mixing got worse. If I put the cavity in the wrong place let me know. Eric Lemmon WB6FLY wrote The first question that enters my mind is, were both Micor stations originally built as repeaters, with the extra filters and shielding plates,or are one or both base stations that have been converted to repeaters? I built our repeater. It's the 146.76 machine. It was originally a pager TX. All shielding and the lo pass TX filter is in place. I have looked at it with a spectrum analyzer and see no other signal than 146.76. I have no idea as to what the other repeater was made from. I will take a second look at their TX. The next time I go down there I plan to take a 50 watt radio and connect it to their duplexer to try to eliminate or prove their PA has a problem. The second question is, are either or both repeaters equipped with ferrite isolators? The 146.76 has no isolator. The 147.36 has a brand new, I believe Sinclair, isolator that was factory built for this frequency. The isolator has no affect on the problem although I don't think it's installed properly. I did not notice when I was there but I think it's mounted on a steel plate. Also there in no cavity between it and the duplexer. The mixing is there with or without the isolator in line. They paid big bucks thinking this would fix the problem. By the way they also replaced their antenna and feed line which may have made the mixing worse. John wrote I hate to tell you, a definite way to eliminate the problem, is a frequency change so that the output of the two transmitters are no longer not 600 khz apart. Funny that`s the first thing I told them. I am familiar
Re: [Repeater-Builder] GE Nomenclature
Check the Doug Hall web site for nomenclature breakdown. The 66 is VHF High split, but I don't remember the rest of the number without looking. Gary - K7NEY - Original Message - From: Ian Miller To: Repeater-Builder@yahoogroups.com Sent: Tuesday, November 11, 2008 11:48 AM Subject: [Repeater-Builder] GE Nomenclature Hi guys. THanks to all who looked up those transistor numbers. One more P I T A question. Our club received a Exec II base station with the folling combination: F156KAU66A TX: 124-A RX: 89-1 I did try to search this on google with no result. Does someone know what this is? We were told its on UHF - I havent had a chance to see it yet. Thanks Ian VA2IR
Re: [Repeater-Builder] GE Nomenclature
Here's the link to Hall Electronics, Exec II nomenclature. http://www.hallelectronics.com/getech/053.htm Gary - K7NEY - Original Message - From: Ian Miller To: Repeater-Builder@yahoogroups.com Sent: Tuesday, November 11, 2008 11:48 AM Subject: [Repeater-Builder] GE Nomenclature Hi guys. THanks to all who looked up those transistor numbers. One more P I T A question. Our club received a Exec II base station with the folling combination: F156KAU66A TX: 124-A RX: 89-1 I did try to search this on google with no result. Does someone know what this is? We were told its on UHF - I havent had a chance to see it yet. Thanks Ian VA2IR
Re: [Repeater-Builder] Scanner as repeater receiver?
Most scanners have an extremely broad front-end and as such would be extremely sensitive to de-sense. Hook it up and let it receive a signal and then key a transmitter next to it and see what happens. Gary - K7NEY - Original Message - From: jstechnicalservice To: Repeater-Builder@yahoogroups.com Sent: Monday, August 11, 2008 2:09 PM Subject: [Repeater-Builder] Scanner as repeater receiver? Has anyone used a good quality scanner as a receiver for a repeater and if so, how well did it work? I'm contemplating a Radio Shack PRO-2055 as it seems to have good receive capability and picks up signal better than some of our mobile radios. Jeff Skaggs Concord-Greene FD
Re: [Repeater-Builder] IFR 1100S
diodes or filter caps in the power supply itself Gary - Original Message - From: [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Thursday, December 13, 2007 7:25 PM Subject: [Repeater-Builder] IFR 1100S OK. I have the 1100S with the bad supply in my hands. There is a 7.5 amp fuse on what I think is the DC side that is blowing. It is blowing with the supply out out of the 1100S. The fuse looks melted so I am guessing over current? The trouble shooting section in the maintenance manual that is on the RB website seems to assume that the fuse is OK before doing the testing. Any suggestions on what might cause this fuse to blow without even being hooked up to the unit? Thanks, Vern
Re: [Repeater-Builder] Failed MastrII
The Part Number stamped into the casting is 19E500952 Anybody got one? Thanks, Gary - K7NEY - Original Message - From: Gary Hoff To: Repeater-Builder@yahoogroups.com Sent: Thursday, October 18, 2007 10:17 AM Subject: Re: [Repeater-Builder] Failed MastrII He'll make a trip to the hill to get the number if possible or at least find out how many final transistors. Gary - Original Message - From: Nate Duehr To: Repeater-Builder@yahoogroups.com Sent: Thursday, October 18, 2007 3:11 AM Subject: Re: [Repeater-Builder] Failed MastrII On Oct 17, 2007, at 8:57 PM, Gary Hoff wrote: Buddy of mine has lost the amplifier section of his MASTR II repeater. Need a base station transmitter or in worse case a Mobile transmitter complete. This is a high band unit presently on 147.2. Anybody have one laying around that is surplus to your needs? Gary - K7NEY Old style -- 4 final transistors or ... New style -- 3 final transistors ... ... on the final board? The GE part number from the casting would be helpful in knowing what he has. Rebuilding a station PA with the wrong mobile PA boards would be a real bear. ;-) If nothing else, post a photo -- they're easy to tell apart if you've seen both, and we could tell you which he has. -- Nate Duehr, WY0X [EMAIL PROTECTED]
Re: [Repeater-Builder] Failed MastrII
He'll make a trip to the hill to get the number if possible or at least find out how many final transistors. Gary - Original Message - From: Nate Duehr To: Repeater-Builder@yahoogroups.com Sent: Thursday, October 18, 2007 3:11 AM Subject: Re: [Repeater-Builder] Failed MastrII On Oct 17, 2007, at 8:57 PM, Gary Hoff wrote: Buddy of mine has lost the amplifier section of his MASTR II repeater. Need a base station transmitter or in worse case a Mobile transmitter complete. This is a high band unit presently on 147.2. Anybody have one laying around that is surplus to your needs? Gary - K7NEY Old style -- 4 final transistors or ... New style -- 3 final transistors ... ... on the final board? The GE part number from the casting would be helpful in knowing what he has. Rebuilding a station PA with the wrong mobile PA boards would be a real bear. ;-) If nothing else, post a photo -- they're easy to tell apart if you've seen both, and we could tell you which he has. -- Nate Duehr, WY0X [EMAIL PROTECTED]
[Repeater-Builder] Failed MastrII
Buddy of mine has lost the amplifier section of his MASTR II repeater. Need a base station transmitter or in worse case a Mobile transmitter complete. This is a high band unit presently on 147.2. Anybody have one laying around that is surplus to your needs? Gary - K7NEY
Re: [Repeater-Builder] astron rs 35a
Pass transistors are the usual culprit. Gary k7ney - Original Message - From: mike To: Repeater-Builder@yahoogroups.com Sent: Wednesday, February 28, 2007 5:17 PM Subject: [Repeater-Builder] astron rs 35a my power supply keeps blowing the fuse changed the pc board i dont know where to go nent any help is apperacited thanks kd5ntp
Re: [Repeater-Builder] RE: Don't miss it
Boy, what math skills 2007 is 1 year 100 years is 2106 and it'ss happen every century after that too. Gary - Original Message - From: hq54 [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Monday, April 03, 2006 1:28 PM Subject: Re: [Repeater-Builder] RE: Don't miss it Nope, in 100 years it will be 2007, so it will be 2/3/4 07. Michael -Original Message- From: DCFluX [EMAIL PROTECTED] Date: Mon, 3 Apr 2006 12:18:52 To:Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] RE: Don't miss it Wouldn't it happen again in exactly 100 years? On 4/3/06, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: Original Message Subject: RE: Don't miss it Date: Mon, 3 Apr 2006 10:37:36 -0700 On Wednesday of this week, at two minutes and three seconds after 1:00 in the morning, the time and date will be 01:02:03 04/05/06. That won't ever happen again. You may now return to your (normal ?) life. Yahoo! Groups Links Yahoo! Groups Links 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] RC-10
MCC has a web site http://home.earthlink.net/~mccrpt/ and there is also a yahoo group for MCC controllers. Maybe you can get some help there. I have a RC-100 but never seen a RC-10 Gary - K7NEY - Original Message - From: J. G. Adams, Jr [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Friday, December 02, 2005 7:28 AM Subject: [Repeater-Builder] RC-10 I'm looking for a manual and any other info on a Micro Computer Concepts RC-10 controller. Can tou program it over the air and how do you reset the controller to the default values Thanks, Jerry Adams W4PX 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] IFR 1200/A Service Monitor
I've not found a way on the 1600 to do that, I think they are similar. The 1600 will measure the difference between the signal and the oscillator setting but you have to know approximately what the signal is you're trying to measure before it works. Gary - K7NEY - Original Message - From: Jim Cicirello [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Tuesday, June 21, 2005 10:17 PM Subject: [Repeater-Builder] IFR 1200/A Service Monitor A question for someone who has working knowledge of the IFR 1200/A Service Monitor. Will this monitor act like a frequency counter and read frequencies off the air? I have been unable to find the answer. Thanks in advance. JIM KA2AJH 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] duplexer tuning - help
Not in Indiana, but a comment. I Used one of those Duplexers years ago. Be careful where you locate it. Extremely sensitive to temperature variations. We had it on a mountaintop and retired it after the first winter. Gary - K7NEY - Original Message - From: Paul [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Thursday, April 14, 2005 9:33 PM Subject: [Repeater-Builder] duplexer tuning - help I think we located the old repeater and duplexers that used to be here in our little one horse town in northern indiana but I am sure that after sitting in storage ,being moved from place to place and just years of neglect they will probably need to be cleaned and retuned is there anyone out there in northern indiana who could help me with this task ? the tuning part that is (I can clean them ) I do not have service monitors or spectrum analyzers all i have is a wattmeter and an old signal generator (HP tube type heavier than most new cars) these duplexers are a homemade 2 meter duplexer from an old qst artical by John j. Bilodeau w1gan. they are made from 4 inch copper pipe i have the equipment to tune them like the artical says with simple equipment but if it could be done better I would opt for that method they had worked very well for years and I would like to see the repeater up and running again anyone who could help please e-mail me thanks Paul (n9fco) 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: New poll for Repeater-Builder (member checkout)
I agree with Skip. It seems that because people have a different opinion of the word build, it is an extreme overreaction. Nothing Russ ever posted offended me, If I didn't agree, I just deleted. Don't know why everyone else can't do likewise Gary - K7NEY - Original Message - From: skipp025 [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Friday, March 25, 2005 10:37 AM Subject: [Repeater-Builder] Re: New poll for Repeater-Builder (member checkout) I typed out a long reply to Kevin's post back to Russ, which I believe Kevin stated near the end he was going to pull the plug on Russ. To quickly sum-up the now deleted reply, I said Russ should not be deleted from the group, else I had to seriously think about and would probably un-subscribe myself. I provided an actual Amateur Related event (story) which is very similar to what's going on here on the group right now. Then I felt it would do no good to post it... so in the trash it went. Much as I really enjoy the group, I'll probably be leaving if member deletion happens because the wrong raw nerve is/was touched. cheers, Skipp skipp025 at yahoo.com [EMAIL PROTECTED] wrote: A few points Russ owns radio stations so what business does he promote here? I work for a company. I do not own it nor does Russ. Yes we can do things around here and I mite say so. But we are so busy here many time we can't help the Hams. When we do many time we do not charge. If there is something that I know and can help with, I will if not I keep silent and go on about things. I am not a Ham so I do not need to see a call. I do not have a Ham call listed any where as you stated. Yes I know Russ he is a very nice person I see him help many people, he just had converted over 20 900 MHz radios and gave them to all the older Hams in the area. Then he gave 8 900 MHz radios to all the Metro-Comm control oops'. This was all out of his pocket. So bad guy I think not. This vote is crap. Plain and simple WRONG! So toss everyone off whom does not bow down and kiss your feet. None of this is helping any one fix or BUILD any thing and is just not good. Have a happy Easter! Dean 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] Duplexer Loss Question
db = 10 Log(P-out / P in) According to my slide rule, P out / P in would be about .707 for 1.5 db .707 X 150 = 106 watts Somebody correct me if I'm wrong. Gary - K7NEY - Original Message - From: w9mwq [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Tuesday, March 22, 2005 11:59 AM Subject: [Repeater-Builder] Duplexer Loss Question I am curious with a set of TX-RX duplexers at 1.5 insertion loss, input power of 150 watts, what would be the power output? Need to know, as I don't think they are tuned correctly, or something might be wrong here. Mathew 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] Spectrum Analyzer
I used to tune them that way also, and thought I did well, but after I got access to a Spectrum Analyzer with tracking generator, I find it much easier and more accurate. Maybe because the pattern is visual when you are tuning with the tracking generator and analyzer. I've taken duplexers I tuned the old way and put them on the service monitor and found I could get 8 or 10 db better with the analyzer. You use what you have, and I sure would use the analyzer/generator combination if I had it. Gary - K7NEY - Original Message - From: Michal Smialowski To: Repeater-Builder@yahoogroups.com Sent: Tuesday, March 22, 2005 10:55 AM Subject: [Repeater-Builder] Spectrum Analyzer I have always tuned duplexers just using a signal generator and a radio receiver. Peaking the passband and then going for the deepest notch for the reject. Although this seems to work, the results haven't been spectacular. I realize that there are many variables to consider. My question is, does using a spectrum analyzer and a sweep generator ( I am guessing here) make the process better, and if it does, how so ie what is the principle behind it? Thanks Mike Smialowski VE7SML Smithers BC Canada 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] linking contrrolers
Any 2 port controller one at each end, I think all of the controller makers offer a 2 port controller. Link RLC-1, CAT series has one, I have a MCC RCC-100 that will do that. Do a google on Repeater controllers and you'll get a bunch of options. Gary - K7NEY - Original Message - From: Warren Beaulé [EMAIL PROTECTED] To: repeater-builder@yahoogroups.com Sent: Monday, March 14, 2005 12:15 PM Subject: [Repeater-Builder] linking contrrolers I have two repeaters one at 145.390- the other at 145.330- about 65 miles apart one at 3000ft the other at 1750ft Nothing but flat land between I want to link with 443.450 and 448.450 what type of controlers do I need and how do I do this. Help __ Post your free ad now! http://personals.yahoo.ca 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] Help with Duplexer ID
Diameter of the cavity doesn't necessarily determine frequency. the following link might help. http://www.emrcorp.com/images/tech_papers/tech_cover/antenna_duplexors(15-26).pdf Gary - K7NEY - Original Message - From: Joe [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Friday, March 11, 2005 5:40 AM Subject: Re: [Repeater-Builder] Help with Duplexer ID 22 1/4 is the circumference? That would make them about 7 in diameter. Sounds like 800-900Mhz equipment. Wacom was making some custom cans for the 900Mhz paging industry back a few years ago. Joe Don [EMAIL PROTECTED] wrote: = The Size is 10 In High and 22 in around 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] Duplexer Retuning TXRX 28-37-02A Help
If the Service monitor has a tracking generator in addition to the spectrum analyzer, look on the repeater builder web site for an article on tuning the Wacom Duplexer, think it was a 641, and it shows you how to hook it up and everything. Same philosophy applies regardless of the type of duplexer. Gary - K7NEY - Original Message - From: w9mwq [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Thursday, March 10, 2005 3:54 PM Subject: [Repeater-Builder] Duplexer Retuning TXRX 28-37-02A Help Due to the recoordination of my repeater, I'm looking for that Elmer to help me along the way retuning this set of duplexer's. I have the tuning instructions and have a Cushman CE-6030 service monitor with an analyzer, but not sure just what to do. I have everything it talks about in the instructions with the exception of a RLB-150 Bridge, and I believe this may be the same thing I built called an iso-tee, might be incorrect. But if someone is willing to help me with this endeaver, it would be greatly appreciated, as the funds are short in supply to send them back to get done by the factory. There is a total of six cans. And if I read it right, each one has to be tunned independently, then put all together and tuned together. I've order the new crystals which will be here next weekend, so that is when I will begin this project to get the system back up on the air. Thanks Mathew 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] Going got Rough, Forced to change Freq, Need Answers
Mathew, As a former freq coordinator myself, it seems to me that this is a completely illogical situation unless there is something I don't know. If both repeaters were properly coordinated in the first place, and there is interference from a user of one getting into the input of the other, that's what we just used to have to live with. It can only be prevented by the user himself using great care to avoid the other machine. If they had different PL's it would help and should keep the remote receiver from keying up and feeding the other repeater. I personally don't see how they could hold you responsible for this type of interference and request you change frequencies, it appears to be a completely unreasonable request and seems that some coordinator is trying to take the easy way out at your expense. And, if there is a problem, it seems it is the coordinator that screwed up and not you. Gar - Original Message - From: "Mathew Quaife" [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Thursday, February 24, 2005 12:41 PM Subject: RE: [Repeater-Builder] Going got Rough, Forced to change Freq, Need Answers All understood there, but the kicker is that my equipment did not interfere with his repeater, it was a user that is about 70 miles away that got into one of his remote receiver's. I'm considering the fight of staying my grounds, and letting the coordinator know that if my system was the cause, fine, but a user is the culprit, how does that affect me. So to say, any frequency by regulations is allowed simplex operation, and should one decide to go off by say 10kc's and talk and if the output of the repeater interfere's, they should shut the repeater off, because, in this sense of his offering's, is the last to come, the first to leave. I believe all the frequencies were simplex before they became duplex. And answer is that I doubt very seriously that any of the remote receiver sites here in Indiana are coordinated. How could they be, in fact anywhere, that only reduces the 100 mile radius they attempt to maintain in coordinating repeaters. Also, both repeaters used the same 131.8 PL. Mathew -Original Message- From: Bob Dengler [mailto:[EMAIL PROTECTED] Sent: Thursday, February 24, 2005 11:06 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Going got Rough, Forced to change Freq, Need Answers At 2/23/2005 03:46 PM, you wrote: Well it seems that I am told I have to change frequencies, has itthat one of my users interferred with the same troublesome repeaterI've had all along, and now the coordinator says I have to move.Not sure how well all the equipment will handle the change. Here iswhat I have as equipment, and will it all make it there. We aremoving from 146.925- to 145.410-, and the expense is the last thingI needed right now.GE MASTR PRO ER41 Receiver So you'll be dropping the RX about 1.5 MHz. Never had a problem with the VHF Mastr Pro RX I took down to 144.84. Vocom Amp, tuned for 146.925and then to top if off, I just got the phasing harness for the DB224and it was cut right for 146.925. The phasing harness is broad enough that you won't see a difference at the new freq. My main transmitter is the (no arguements please), Maggorie HiProtransmitter exiting 2 watts to the vocom amp.TX RX Duplexers.How low in frequency will the MASTR Pro go before I loose qualitysensitivity, right now, it's about .15 uv with a preamp, andreceives excellent. It should work fine. In fact, the preamp ahead of it will make any small degradation in the RX noise figure as a result of the move negligible. The vocom amp is model #VVC200-2ref and wasdesigned for the 146 Mhz range.I'm sure the duplexers should not be a problem, other than gettingthem re-tuned. Thoughts! I don't see any problems other than all the work involved in retuning everything. What anger's me the most about this, is that the repeater owner wentstraight to the coordinator, did not bother to talk with me. Ichanged the PL of the repeater. Your user may have been getting too good of a signal into the other repeater's RX. Even with everything CTCSS-protected, a user of one repeater can still block signals intended for the other system. Other sad part is, the user that was getting into their system wasnot getting into the main receiver, but rather a remote site. Iwonder how tight his receiver really is, and is it a synthesizedradio, or something of quality. If it's on-channel, it doesn't matter so long as the remote RX of the other system is coordinated. A "quality" RX will not reject on-freq. signals just because they're "intended" for another repeater. Bob NO6B Yahoo! Groups Links -- No virus found in this incoming message. Checked by AVG Anti-Virus. Version: 7.0.300 / Virus Database: 266.4.0 - Release Date: 2/22/2005 -- No virus found in this outgoing message. Checked by AVG
Re: [Repeater-Builder] 900 mhz pa equip
Don't know if this'll help but there has been a seller on Ebay selling complete 300 watt Purc 5000 transmitters and he's down to $329.00 for the whole unit and isn't getting any bids. Gary-K7NEY - Original Message - From: Larry Williams [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Thursday, May 20, 2004 3:05 PM Subject: [Repeater-Builder] 900 mhz pa equip Anyone know the value, if any, for 900 mhz pa units that came out of cellular sites. We have about a hundred or so and they have to go. No room. I think I saw a thread for them some time back but didn't pay attention to it. Are they of use? 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] Help on Interference
Steve's suggestion s are good. We had similar problems in California with 15 Khz splits particularly when the user of the adjacent channel was a bit off frequency. It is most likely the user getting into your machine and not the repeater unless there is some kind of mixing going on. PL (CTCSS) is the best solution cause you probably can't control their users and keep them on frequency and their deviation down. Gary-K7NEY - Original Message - From: Steve S. Bosshard (NU5D) [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Monday, April 26, 2004 6:28 PM Subject: RE: [Repeater-Builder] Help on Interference Each signal is about 10 to 12 Khz wide. You are in each other's pass band. Public safety had similar problems here - 15 Khz channel spacing and 20 kc wide channels using geographic separation. Suggestions - use different sub audible tones to reduce annoyance interference. Both parties reduce modulation to +/- 3.5 Khz peak transmitter deviation. QSY? Go narrow band, different RX filters and 2.5 Khz peak deviation. Regards, Steve 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: cor logic circuit thoughts
No, Brendan, my idea was to use the point you were originally using that you said went from 7V to .5 V when a carrier appeared. We are talking about purely DC voltages here, no audio is involved. a 10K pot will work fine. 1 lead to 12V and opposite to ground then take the slider (rotor) and run it to the + input of the Op Amp. Take your swinging voltage and apply it to the - input. Output should go high when + input is high relative to - input and low when it is low relative to - input. Makes a dandy DC switch and after all, that's what a COS is, a DC switch. Adjust your 10K resistor voltage divider to about 3.5 volts to start then move it one way or the other to get the best snap action by watching the output with a meter. That swinging output can then drive a mini-relay or the base of a transistor. Don't try and key the PTT line with the OP Amp, it won't sink enough current. Hope that explains it better. If you still have trouble you can contact me off line. Gary - Original Message - From: bsoutheyoz [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Thursday, April 01, 2004 6:39 AM Subject: [Repeater-Builder] Re: cor logic circuit thoughts This sounds like the answer I need. I think Joe suggested building an op-amp comparator earlier. Can someone who has used a 741 before please check that my wiring is correct? I will buy the components this weekend. Pin 2 : Reference input 12 Vdc via trim pot (what size pot to use to approximate reference for 1 V P-P audio? Pin 3 : Audio input Pin 4 : Gnd Pin 6 : + Vdc COR output Pin 7 : + 12 Vdc in And reverse pins 2 and 3 if output swings the wrong way. Thanks Gary! Brendan --- In Repeater-Builder@yahoogroups.com, Gary Hoff [EMAIL PROTECTED] wrote: Boy, maybe I'm wrong but it sure seems like this is being made more complicated than it should be. Use a 741 or equiv. Op Amp as a DC voltage comparator. Establish a reference voltage on the + input with a pot or a couple resistors as a voltage divider. Attach the voltage that is swinging from 7V to .5 V to the - input. When the voltage on the - input goes below the reference voltage, the output swings hard. If the output doesn't go the way you want, reverse the inputs. I've been using this type of circuit for years clear back to the old tube type prog line and Motorola sensicon strips. you can move the reference voltage along the curve of the voltage swing to where ever it works the best. That's why I like to use a 10 turn pot or similar to establish the reference voltage, it gives some flexibility to the circuit. Gary - K7NEY 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] Re: cor logic circuit thoughts
Boy, maybe I'm wrong but it sure seems like this is being made more complicated than it should be. Use a 741 or equiv. Op Amp as a DC voltage comparator. Establish a reference voltage on the + input with a pot or a couple resistors as a voltage divider. Attach the voltage that is swinging from 7V to .5 V to the - input. When the voltage on the - input goes below the reference voltage, the output swings hard. If the output doesn't go the way you want, reverse the inputs. I've been using this type of circuit for years clear back to the old tube type prog line and Motorola sensicon strips. you can move the reference voltage along the curve of the voltage swing to where ever it works the best. That's why I like to use a 10 turn pot or similar to establish the reference voltage, it gives some flexibility to the circuit. Gary - K7NEY 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.
