Re: [Repeater-Builder] Re: LMR-1200
2 additional connectors and a jumper at the antenna is still a potential source of trouble in the future, especially for someone who may not be familiar with how to install them properly. LDF4-50A is used extensively and almost exclusively in the cellular business for antenna jumpers. Joe -- Original message -- From: [EMAIL PROTECTED] Good N connectors are virtually lossless @ 450 MHz, 4 ft. of RG-214 (2 ft. each jumper) has 0.2 dB loss. I know there's a difference of opinion on this subject, but I'd never directly connect LDF4-50 to an antenna. ---BeginMessage--- At 1/27/2007 06:47, you wrote: LMR-1200 has about .9dB loss for 100 feet LDF4-50A has about 1.45dB loss for 100 feet At first glance, it looks like you can gain a little more than 1/2dB by using LMR-1200. Now. the real world. LMR-1200 will require a jumper at the top and the bottom of the cable run. (It's too big to connect directly to the antenna or the duplexer at the bottom). This means that you will have to have 4 additional connectors and 2 short lengths of jumper cable when using LMR-1200. This will add up to much more loss than the 1/2dB you saved by using LMR-1200. Good N connectors are virtually lossless @ 450 MHz, 4 ft. of RG-214 (2 ft. each jumper) has 0.2 dB loss. I know there's a difference of opinion on this subject, but I'd never directly connect LDF4-50 to an antenna. However, the real reason not to use LMR-1200 in duplex feeds is the braid-over-foil shield, which will eventually cause desense IMD. The key word is eventually: maybe 6 months after install, maybe 30 years. Nothing like solid copper to keep those stray electrons in line ;) Bob NO6B ---End Message---
Re: [Repeater-Builder] Re: Phelps Dodge 526 frequency range
They do have excellent notch rejection, but very poor bandpass qualities. If you look at a wide-band spectrum plot, say from 0 to 1000 MHz, you'll find the two notches, and many peaks, but the majority of the signal gets through with nearly no attenuation. It's almost flat from 0 to maybe 400 MHz, and flat from 500 to 1000 MHz, with perhaps 5dB loss. I've seen other duplexers that have two notches and two peaks, and everything else is attenuated a considerable amount (over 60dB). Not so with the Celwave/PD 526 series. Call or write to Celwave (now RFSystems) and ask them for the cutting chart for units using RG400. Last time I tried that, every technician I spoke with told me, in no certain terms, that they NEVER used RG400 or RG142, yet I have seen photos and one actual unit that was factory fresh and had that unmistakeable tan colored, RG58-size teflon coax that I know is not RG214. Maybe they finally realized that they DID make them that way. I've never been able to figure out the actual lengths of the coax jumpers on these things. Of course, the coupling loop inside the cavity probably has something to do with the length too. Since I don't want to drill the rivets to find out what's inside, I'll stick with the cables the factory sends out. By the way, my first unit had RG8 with clamp-on male N connectors. Every one had been twisted so much that pieces of braid were shorting out the center pin and there was no longer a good electrical ground circuit. So I bought one brand new set of cables for 440-450 MHz for $250. When I had to do this the second time, I built my own; 6 ft of RG214 and a dozen crimp-on male N connectors cost a whole lot less than $250. Bob M. == --- mdnosliw [EMAIL PROTECTED] wrote: --- In Repeater-Builder@yahoogroups.com, mdnosliw [EMAIL PROTECTED] wrote: I recently picked up a Phelps Dodge 526-5 on e-bay. The auction stated that it would work in the ham band. When I received it I discovered that it was a 470 to 512 mhz model. If I replace the cables can I get it to tune down to the 440 segment of the band. Thanks Mark Thanks for the info Bob. I know that there are different versions of the notch filter, but I think that relates to filter bandwidth. Yes I have the cable length chart, but I think I prefer to use RG- 400.Should not be a big deal to do the math. I have 3 526's and think it is the best Uhf duplexer that can be had. Thanks Mark No need to miss a message. Get email on-the-go with Yahoo! Mail for Mobile. Get started. http://mobile.yahoo.com/mail
Re: [Repeater-Builder] Antenna on the side of a water tower
For a water tower, I would imagine the backside null is rather substantial. A club I was associated with more than 20 years ago tried the side mounting of an 2 meter antenna on the railing of a old style water tower (four legs supporting the Ball. It performed as expected with deep, very noticeable (on the air) nulls off the back. However, if that is all you can get, then go for it. I have seen guys mount a Rohn 25 type tower on the platform where the railing is, mount the antenna on top of the tower section(s) and then the top of the antenna will see over the top of the water tower. I guess it should work. However. I bet there is a mechanical situation that has to be worked out to insure mechanical integrity during high winds. If you can bolt the tower top to the ball, that would help. I have seen that also. Roger W5RD From: Dave VanHorn [EMAIL PROTECTED] Date: 2007/01/26 Fri PM 12:16:39 CST To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Antenna on the side of a water tower Can anyone point me to something that will show me the antenna pattern for a VHF and UHF antenna mounted on the side of a water tank at different distances from the tank? I've been offered a site, but I can't have top mount, I have to go on the side. I have the mfgr's docs showing pattern with different distances between the loops and the mast, but I don't have any info on how the big metal tank reflection will disturb the pattern. I'm sure there's an optimal distance, but I don't know what it would be. Roger White Murphy, Texas
RE: [Repeater-Builder] Re: Antenna on the side of a water tower
They are combined. Nextel does this and calls it a Quasi-Omni site. There are some drawbacks to it, but it actually works quite well. Most panel antennas used are 90 or 65 degree antennas. The biggest drawback is the 6dB hit that you take on receive and some strange nulls between the sectors. The 3-diversity receive scheme they use seems to help in these areas. As you stated, a voter would be the best solution to the water tank site. But. what would you do about transmit? Switching the transmit would eliminate the omnidirectional coverage that you need for mobile-to-mobile communications. This would start to get to be a very complex system. I was trying to keep it simple a affordable. Joe -- Original message -- From: Eric Lemmon [EMAIL PROTECTED] Joe, I don't think those three panel antennas are combined at all. Most cellular and PCS providers are using 120-degree panel antennas to cover three 120-degree sectors, each with its own base station, effectively tripling their capacity. The older omnidirectional antenna cell sites- usually a cluster of fiberglass vertical pairs, one pointing up and one pointing down- are being retrofitted with panel antennas. Panel antennas are much easier to camouflage, and they can be physically tilted for better close-in coverage. One solution to obtaining omnidirectional coverage around a water tank- assuming your site owner will allow you to put up three antennas- is to use a voter to select the best signal from three low-gain Yagi antennas, and switch the transmitter output to that antenna. I suppose combining would work, but I wonder if destructive cancellation will rear its ugly head. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Joe Sent: Saturday, January 27, 2007 3:17 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Re: Antenna on the side of a water tower snip One of the carriers does something similar. They put panel antennas on each of the 3 faces, then combine them into one omni-directional antenna system. It does work. I know of several water tank installations that are just like this. Joe ---BeginMessage--- Joe, I don't think those three panel antennas are combined at all. Most cellular and PCS providers are using 120-degree panel antennas to cover three 120-degree sectors, each with its own base station, effectively tripling their capacity. The older omnidirectional antenna cell sites- usually a cluster of fiberglass vertical pairs, one pointing up and one pointing down- are being retrofitted with panel antennas. Panel antennas are much easier to camouflage, and they can be physically tilted for better close-in coverage. One solution to obtaining omnidirectional coverage around a water tank- assuming your site owner will allow you to put up three antennas- is to use a voter to select the best signal from three low-gain Yagi antennas, and switch the transmitter output to that antenna. I suppose combining would work, but I wonder if destructive cancellation will rear its ugly head. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:Repeater-Builder@yahoogroups.com] On Behalf Of Joe Sent: Saturday, January 27, 2007 3:17 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Re: Antenna on the side of a water tower snip One of the carriers does something similar. They put panel antennas on each of the 3 faces, then combine them into one omni-directional antenna system. It does work. I know of several water tank installations that are just like this. Joe ---End Message---
[Repeater-Builder] Link-Comm - Micor carrier squelch timing (was GE squelch)
Bob, et al, Bob wrote: FWIW, I never use pin 10 at all; Kevin wrote: I try to use that pin when I can, and prefer it over the open emitter shunt switches. Incidentally, the Link-Comm board uses the 2.2 uF cap / pin 10 combination to drive the COS output buffer... FWIW Bob wrote: Really! I noticed some decay problems with an RLC-MOT we have on an SCom 7k. I've always attributed it to COS line propagation delay in the controller, but perhaps the 2.2 µF cap is the major culprit. We solved the problem by using the onboard audio gating, which I see uses pins 6 7 of the Micor squelch IC. Maybe we can ask Link-Comm to do a timing test on their unit and then change the 2.2 uF capacitor on pin 10 to something else and see if it changes the attack/decay of the COS action? Steve or Allan - you out there? Kevin Custer
[Repeater-Builder] Re: Too fast squelch on GE Master
I use the Link Comm audio delay and stretch the slow squelch out (on the GE) with a larger cap. Seems to work pretty well on this Mastr II and RLC Club combo. 73
[Repeater-Builder] MVP ICS Problem
Greetings, I am having a problem with a 440 repeater that I am putting together. I started with a MVP custom that I converted to 70cm and duplex modded. The radio tuned quite nicely on 443.800 tx and 448.800 rx. Tx and Rx well before the duplex mod. I made sure to get Hi side LO xtal for my rx also. I installed the ICS Basic controller and the COS is working, and ptt working great. But I have a horrable feedback injection. I can turn down the audio on the controller to its lowest setting and still have the feedback. I can turn the radio's PA down to 500mw and the feedback goes away, but there is still noise in the audio. When I turn the pa back up or even to from 2-10w the noise is back even in the squelch tail. If I disconnect the controller, my feedback goes away. I have also directly connecting my rx audio to my tx audio and keying the xmitter, and using my ht supplying an imput signal and get good audio out at full power. But when I put the controller back in line the feedback resumes. I also noticed waiving my hand over the controller while the feedback is happening changes the frequency of the feedback. Any ideas? Thanks and 73 de Joe KB5VJY -- First repeater project not working out!
Re: [Repeater-Builder] Link-Comm - Micor carrier squelch timing (was GE squelch)
I will see if I can perform that test on Monday AM and post the results. BTW, the typical propogation delay through all the controllers is less that 5mS, so pretty fast. Allan Overcast KF7FW Link Communications, Inc. www.link-comm.com Kevin Custer [EMAIL PROTECTED] wrote: Bob, et al, Bob wrote: FWIW, I never use pin 10 at all; Kevin wrote: I try to use that pin when I can, and prefer it over the open emitter shunt switches. Incidentally, the Link-Comm board uses the 2.2 uF cap / pin 10 combination to drive the COS output buffer... FWIW Bob wrote: Really! I noticed some decay problems with an RLC-MOT we have on an SCom 7k. I've always attributed it to COS line propagation delay in the controller, but perhaps the 2.2 µF cap is the major culprit. We solved the problem by using the onboard audio gating, which I see uses pins 6 7 of the Micor squelch IC. Maybe we can ask Link-Comm to do a timing test on their unit and then change the 2.2 uF capacitor on pin 10 to something else and see if it changes the attack/decay of the COS action? Steve or Allan - you out there? Kevin Custer - Have a burning question? Go to Yahoo! Answers and get answers from real people who know.
[Repeater-Builder] F/S 120 Watt Midland UHF Continuous Duty Repeater Amplifier
F/S 120 Watt Midland UHF Continuous Duty Repeater Amplifier This unit was our shop spare and saw about 96 hours worth of use. It takes 5 watts to drive and puts out 120 watts. I believe these were manufactured for Midland by TPL The unit is rack mountable and comes with rack mount kit. We currently have one plus a spare tuned down to 444.XXX running at 110 Watts I will include a copy of the Amplifier section of the Midland Manual as well. I am asking $350.00 plus shipping e-mail me directly for pics. Vince
Re: [Repeater-Builder] MVP ICS Problem
At 1/28/2007 06:59, you wrote: The moment you stated that waving your hand over the controller says that you have an RFI problem. If that controller is a board that is just meant to go in the radio, you will need to shield it well, and possibly find out what inside the radio is leaking RF that gets into the controller. Better yet, mount the controller in an RF-tight box with EMI feedthroughs on the power. The I/O will be difficult to bypass; I've never found it necessary to do that but your situation may be different. Bob NO6B
Re: [Repeater-Builder] Link-Comm - Micor carrier squelch timing (was GE squelch)
At 1/28/2007 07:26, you wrote: I will see if I can perform that test on Monday AM and post the results. BTW, the typical propogation delay through all the controllers is less that 5mS, so pretty fast. ..except the RLC-3 RLC-4, unless there's been very recent firmware upgrades that have taken care of that issue. Bob NO6B
[Repeater-Builder] Re: Antenna on the side of a water tower
Which reminds me that I should have mentioned the available scan of club using a series of yagi antennas around a wide tower to obtain a quasi omni pattern. You can probably find the info on the repeater builder antenna page along with the mounting offset paper I mentioned earlier. skipp [EMAIL PROTECTED] wrote: For a water tower, I would imagine the backside null is rather substantial. A club I was associated with more than 20 years ago tried the side mounting of an 2 meter antenna on the railing of a old style water tower (four legs supporting the Ball. It performed as expected with deep, very noticeable (on the air) nulls off the back. However, if that is all you can get, then go for it. I have seen guys mount a Rohn 25 type tower on the platform where the railing is, mount the antenna on top of the tower section(s) and then the top of the antenna will see over the top of the water tower. I guess it should work. However. I bet there is a mechanical situation that has to be worked out to insure mechanical integrity during high winds. If you can bolt the tower top to the ball, that would help. I have seen that also. Roger W5RD From: Dave VanHorn [EMAIL PROTECTED] Date: 2007/01/26 Fri PM 12:16:39 CST To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Antenna on the side of a water tower Can anyone point me to something that will show me the antenna pattern for a VHF and UHF antenna mounted on the side of a water tank at different distances from the tank? I've been offered a site, but I can't have top mount, I have to go on the side. I have the mfgr's docs showing pattern with different distances between the loops and the mast, but I don't have any info on how the big metal tank reflection will disturb the pattern. I'm sure there's an optimal distance, but I don't know what it would be. Roger White Murphy, Texas
[Repeater-Builder] Kenwood KMC-18 Microphone
I just checked the Repeater-Builder Kenwood section that discusses the various microphone wiring schemes http://www.repeater-builder.com/kenwood/kenwood-misc-connectors.pdf for different Kenwood Ham rigs but, no information on commercial radios. Does anyone on this list happen to have a schematic diagram of the KMC-18 DTMF microphone with the modular 6-pin connector on it?? I would like to adapt this mic [change the connector to the 8 pin type] to my Kenwood 440 UHF TM-441A radio. The 441A rig requires a 600 ohm impedance mic [I have the stock factory one but its a little beat up]. It is assumed that the KMC-18 being a Kenwood product, is a 600 ohm mic. Thanks!! Doug W7FDF Vail, Arizona U.S.A. OK to email me off the list if necessary.
RE: [Repeater-Builder] Re: Phelps Dodge 526 frequency range
Call or write to Celwave (now RFSystems) and ask them for the cutting chart for units using RG400. Last time I tried that, every technician I spoke with told me, in no certain terms, that they NEVER used RG400 or RG142, yet I have seen photos and one actual unit that was factory fresh and had that unmistakeable tan colored, RG58-size teflon coax that I know is not RG214. Maybe they finally realized that they DID make them that way. I have two 526's that use RG142B/U for interconnects. One of them appears to be a regular duplexer, the other appears to have been spec'ed for use on a close-spaced combiner/multicoupler (passbands shown as being 250 kHz wide). I've recabled T-band 526's down to 440-470 as well. IIRC, the cable lengths for RG-214/U were 12 to the antenna tee, and 11.5 everywhere else. The loss on the T-band ones seems to be just a tad higher than the 440-470 ones. Perhaps the loops are a little smaller on the T-band ones. Like you, I haven't drilled them out to a comparison over 0.2 dB. By the way, my first unit had RG8 with clamp-on male N connectors. Every one had been twisted so much that pieces of braid were shorting out the center pin and there was no longer a good electrical ground circuit. Yeah, the old ones with RG8 interconnects also tend to have self-noise from the now-tarnished 15+ year old copper braid. Same thing with older PD696's. --- Jeff
[Repeater-Builder] Re: Antenna on the side of a water tower
--- In Repeater-Builder@yahoogroups.com, skipp025 [EMAIL PROTECTED] wrote: Which reminds me that I should have mentioned the available scan of club using a series of yagi antennas around a wide tower to obtain a quasi omni pattern. You can probably find the info on the repeater builder antenna page along with the mounting offset paper I mentioned earlier. Somehow, I don't think the paper pointed to earlier is the one you are talking about.
[Repeater-Builder] Re: Antenna on the side of a water tower
However, if that is all you can get, then go for it. I have seen guys mount a Rohn 25 type tower on the platform where the railing is, mount the antenna on top of the tower section(s) and then the top of the antenna will see over the top of the water tower. Problem is, there's a fire repeater on the top, and they want us on the side, specificially NOT above the side. I'm just looking for a way to predict the pattern(s) so I can plug that into RM, and see if it's worth spending a bucket of money to change to this site.
Re: [Repeater-Builder] Need Tait800 UHF Slimline Documentation Programming
Paul Metzger wrote: It is a T800 Series 1 Slimline which requires the PROMs to be programmed. I need documentation, software, and to find out what hardware (exact models) I will need to acquire in order to program the proms, including cables. All it has is a single rack panel with a T855-20 Receiver, T856-20 Exciter/Amplifier and a terminal strip attached. It has a date on it of October 1996. I need documentation in order to find out how to interface it to a homebrew controller, which will then tie into an AOR Digital Voice modem. I hope to make it into a repeater for the Digital Voice Amateur Radio Association. Any help will be much appreciated ! Thanks ! Paul Metzger KQ6EH Paul, Unless the frequency you are planning to use is a multiple of 100KHz, the Tait Software wont work in southern California (SCRRBA area) as it cannot generate anything except 12.5 or 25 KHz channels and we use 20KHz channels. You will need to find an EPROM eraser and programmer that can program the EPROMS within your units. The formulas for generating the hex values required are (hopefully this will be readable once posted): WORD1 2 3 4 5 6 7 8 REG M M M A A R R R BIT L 0 2 6 0 4 0 4 8 BIT M 1 5 9 3 6 3 7 10 | | | | | | | | M A CH #| | | | | | | |TX FREF=200KHz 0 08 0E 0A 0E 00 0A 00 00698 14 446.860 TX USING 10 KHZ STEPS 1 08 0E 0A 00 01 0A 00 00698 16 446.880 TX USING 10 KHZ STEPS RX FREF=6.4MHz 0 00 0B 09 06 00 00 04 01620 06 441.860 RX USING 10 KHZ STEPS 1 0C 0A 09 08 00 00 04 01620 08 441.880 RX USING 10 KHZ STEPS TX FREQ(MHz) = M * 0.64 + A * 0.01 RX FREQ(MHz) = M * 0.64 + A * 0.01 + 45 Here is the pinout for a stock 855rx and 856tx: pin 855 856 1 line out 1 line in 1 2 line out 2 line in 2 3 line out 3 line in 3 4 line out 4 line in 4 5 RSSITX Enable 6 Audio 1 Audio 2 7 Audio 2 Audio 1 8 Speaker CTCSS 9 +13V+13V 10 +13V+13V 11 Gate/COS outOpto-key + 12 COR 1 Opto-key - 13 COR 2 TX key / PTT 14 Ground Ground 15 Ground Ground You will need to locate a manual for the T855 T856 as there are many possible internal configurations possible due to multiple internal jumpers. If anyone has the manuals in PDF form, I do not know of them. Ed Yoho WA6RQD
[Repeater-Builder] Re: 2 meter repeater
--- In Repeater-Builder@yahoogroups.com, Chuck Kelsey [EMAIL PROTECTED] wrote: Tell us how much money you expect to spend and the group can tell you what you may be able to get for that amount. Chuck - I'll try to give you some details and cost. 2@ Icom F-121, cables, setup and tuned New - $ 750. 1@ Repeater Controller NHRC 3+ $ 200. 1set 4 tube - Tel-wave used Duplexer - $ 850. 1 @ 2 meter dipole stick $ 75. Tech charges to re-tune Telewave Duplexer - $ 175. 65' LMR400 - antenna mast - gable end mount - Lighting arrestor, ground 4@ rods, clamps and ground conductor # 4 bare. Misc. $ 450. That totals about $ 2,500. for mostly new gear. Note: the total cost is over 4 times the cost of the repeater - which is what most people get hung up on. If all the gear isn't of good quality and compatible your results will be poor. When setting up a 2 meter repeater the actual repeater and good quality properly tuned duplexer make or break the system. The cheap duplexers from the far east don't get the job done. If your need is for an inexpensive repeater I suggest you look in to the .70 centimeter equipment as it can be done for a third the cost of a well equipped and setup 2 meter rig Good Luck EasyLyle K4tg0 WQCM810
[Repeater-Builder] Wanted Mastr II Crystals Tx 145.43 Rx 144.83
Looking for the above. Thanks Dave
Re: [Repeater-Builder] Re: 2 meter repeater
I wasn't the one looking, but the guy that was now has the info you posted. The original poster simply said he was looking for a repeater, cheap, then gave no other details of what he was really looking for. Chuck WB2EDV - Original Message - From: Lyle Schultz [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Friday, January 26, 2007 8:56 AM Subject: [Repeater-Builder] Re: 2 meter repeater --- In Repeater-Builder@yahoogroups.com, Chuck Kelsey [EMAIL PROTECTED] wrote: Tell us how much money you expect to spend and the group can tell you what you may be able to get for that amount. Chuck - I'll try to give you some details and cost. 2@ Icom F-121, cables, setup and tuned New - $ 750. 1@ Repeater Controller NHRC 3+ $ 200. 1set 4 tube - Tel-wave used Duplexer - $ 850. 1 @ 2 meter dipole stick $ 75. Tech charges to re-tune Telewave Duplexer - $ 175. 65' LMR400 - antenna mast - gable end mount - Lighting arrestor, ground 4@ rods, clamps and ground conductor # 4 bare. Misc. $ 450. That totals about $ 2,500. for mostly new gear. Note: the total cost is over 4 times the cost of the repeater - which is what most people get hung up on. If all the gear isn't of good quality and compatible your results will be poor. When setting up a 2 meter repeater the actual repeater and good quality properly tuned duplexer make or break the system. The cheap duplexers from the far east don't get the job done. If your need is for an inexpensive repeater I suggest you look in to the .70 centimeter equipment as it can be done for a third the cost of a well equipped and setup 2 meter rig Good Luck EasyLyle K4tg0 WQCM810 Yahoo! Groups Links
Re: [Repeater-Builder] Link-Comm - Micor carrier squelch timing (was GE squelch)
Thank you... (this is very interesting to me) Kevin Custer Allan Overcast wrote: I will see if I can perform that test on Monday AM and post the results. BTW, the typical propogation delay through all the controllers is less that 5mS, so pretty fast. Allan Overcast KF7FW Link Communications, Inc. www.link-comm.com http://www.link-comm.com */Kevin Custer [EMAIL PROTECTED]/* wrote: Bob, et al, Bob wrote: FWIW, I never use pin 10 at all; Kevin wrote: I try to use that pin when I can, and prefer it over the open emitter shunt switches. Incidentally, the Link-Comm board uses the 2.2 uF cap / pin 10 combination to drive the COS output buffer... FWIW Bob wrote: Really! I noticed some decay problems with an RLC-MOT we have on an SCom 7k. I've always attributed it to COS line propagation delay in the controller, but perhaps the 2.2 µF cap is the major culprit. We solved the problem by using the onboard audio gating, which I see uses pins 6 7 of the Micor squelch IC. Maybe we can ask Link-Comm to do a timing test on their unit and then change the 2.2 uF capacitor on pin 10 to something else and see if it changes the attack/decay of the COS action? Steve or Allan - you out there? Kevin Custer
