[Repeater-Builder] Re: fan timer circuit
Re: fan timer circuit I've seen a number of fan delay, time on, time off circuits posted on web. The neat'o web page url I just posted here on the group has one and it might be the one you're looking for. http://www.w1ghz.org/small_proj/small_proj.htm and the fan controller information is about half way down the page with a picture and down-loadable zip file. My own personal preference is to run everything warm and even a lot higher temp than most of you would expect. In a repeater station operation only an RF PA and un-modified Astron Power Supply with an undersized heat sink might get a fan. Never a failure of a well planned installation. Some of our local start-up radio clubs throwing repeater packages in place often start out using and stay with an external RF amplifier designed for mobile operation. Sometimes the amp runs so hot you can't keep your hand on the heat sink but I've yet to see one fail. cheers, skipp Bob M. msf5kg...@... wrote: I would think that the person who designed it, and submitted it for posting on r-b, built and tested it. Did you have a problem with it? Do you think there's an error in the diagram? If so, it should be fixed. Please provide more info. Bob M. == --- On Sat, 12/20/08, Michael Ryan mryan...@... wrote: From: Michael Ryan mryan...@... Subject: [Repeater-Builder] fan timer circuit To: Repeater-Builder@yahoogroups.com Date: Saturday, December 20, 2008, 1:57 PM I was directed by someone on the reflector here some months back, to a cooling fan timer circuit that is posted on the repeater builders website. I wonder if anyone has tried to build this? - Thanks - Mike
Re: [Repeater-Builder] Re: fan timer circuit
Maybe it's just me, but I've never understood the need for a special circuit to run cooling fans. I run my fans from the PTT line using a relay. I have also used a simple chassis thermostat, but prefer using PTT. I suppose you could easily use both methods so that in the event that the equipment remained too warm when PTT halts, the thermostat could keep it running longer. However, I contend that if this is happening, your fans are inadequate and not keeping up with the demand right along. Why the need to continue cooling after the QSO has ended? Just because you can? Chuck WB2EDV - Original Message - From: skipp025 skipp...@yahoo.com To: Repeater-Builder@yahoogroups.com Sent: Sunday, December 21, 2008 12:24 PM Subject: [Repeater-Builder] Re: fan timer circuit Re: fan timer circuit I've seen a number of fan delay, time on, time off circuits posted on web. The neat'o web page url I just posted here on the group has one and it might be the one you're looking for. http://www.w1ghz.org/small_proj/small_proj.htm and the fan controller information is about half way down the page with a picture and down-loadable zip file. My own personal preference is to run everything warm and even a lot higher temp than most of you would expect. In a repeater station operation only an RF PA and un-modified Astron Power Supply with an undersized heat sink might get a fan. Never a failure of a well planned installation. Some of our local start-up radio clubs throwing repeater packages in place often start out using and stay with an external RF amplifier designed for mobile operation. Sometimes the amp runs so hot you can't keep your hand on the heat sink but I've yet to see one fail. cheers, skipp
Re: [Repeater-Builder] Re: fan timer circuit
At 12/21/2008 09:24, you wrote: Some of our local start-up radio clubs throwing repeater packages in place often start out using and stay with an external RF amplifier designed for mobile operation. Sometimes the amp runs so hot you can't keep your hand on the heat sink but I've yet to see one fail. cheers, skipp 70 °C, the upper operating temperature limit of many RF devices, is too hot to touch. However, MTBF will definitely be reduced. In addition, without better cooling the devices board will experience greater temperature extremes, which would result in more failures caused by thermal cycling. Mobile amps often lack adequate power supply bypassing, resulting in a lot of in-cabinet RF coming off the amp's power leads. This can be avoided by feeding the +12V through bypass capacitors or high current EMI feedthroughs, rerouting the - power connection directly to the case instead of through an unbypassed terminal strip. Bob NO6B
[Repeater-Builder] Some Receiver to External Controller Audio choices
Is there a point inside the Mitrek that one can take the audio out to the controller (in this case a Link-Comm RLC-2A)? A low band Mitrek (33Mhz) Depends on what type of audio you want. The high side of the volume control is often a great place to take de-emphasized audio. However, some receivers squelch/mute the audio in the trailing power amplifier section so you will have constant no-signal white noise at your controller input if your circuit uses the trailing Audio Power Amplifier Mute Method. Just to throw a wrench into the mix I'll say that in a few radios... I've also seen the de-emphasis network and CTCSS (PL to you Motorhead types) placed after volume control. These are cute items/tricks you find out when you take a closer look at the circuit diagram and/or descriptions. And... Although a lot of the pure at hearts say nay... There's nothing wrong with terminating the speaker audio into a 22 or 27 ohm 5 watt (min) resistor and take your controller audio across it. The resultant audio should have the CTCSS filtered (if you have the Mitrek CTCSS board in place), squelched and level adjustable from the volume control (pot), which you should probably hide from magic fingers at the repeater site. There are a number of places to inject/apply transmit audio. If you go in at the mic-input the audio should be pre-emphasized for transmit somewhere within that chain (path). I've also added pre-emphasis to the output of some of the external repeater controllers if you inject your tx audio at a higher/ later stage than the transmitter mic input. Hopefully someone with a decent amount of Mitrek to Repeater Conversion experience will pipe up and help you out. If not I know a guy off the list who would probably know and he's Email accessible to provide his 50 cent opinion. cheers, skipp Gmail - Kevin, Natalia, Stacey Rochelle spar...@... wrote: Hi, Is there a point inside the Mitrek that one can take the audio out to the controller (in this case a Link-Comm RLC-2A)? A low band Mitrek (33Mhz) I have downloaded the information fromLou's Mitrek Repeater Conversion and a couple of others which mention a schematic for emphasis before going into the controller. Taking the audio out on pin 11. I would like to leave this out if possible and feed directly? Regards and Merry Christmas Kev. - Original Message - From: Kevin Custer To: Repeater-Builder@yahoogroups.com Sent: Sunday, December 21, 2008 2:40 PM Subject: Re: [Repeater-Builder] Converting a Range 2 VHF Mitrek to Range 1 (WAS: Holiday Special...) Eric Lemmon wrote: Only one of the five front-end coils for a Range 1 VHF Mitrek (HLD4081, 136-146 MHz) is still available from Motorola Parts. That one is part 2480032A07, the violet coil in L1, for $ 4.15. The only option may be to tack on some extra wire to the existing coils. Although modifying the tuning screws may work, I suspect the Q will suffer. Eric, I would think a coil retro like what I make available for the MICOR will also work in the Mitrek. This approach would be way better than tacking some added wire onto the existing coil or modifying the screws in which I know that is a bad idea. Is there something special about the Mitrek front-end that you believe would prohibit such a conversion? It's been a while since I messed with the Mitrek but I don't remember anything that would prohibit the correct length coil to be installed... Kevin
[Repeater-Builder] Re: fan timer circuit
I mostly agree. My thinking is that a fan that runs continuously wastes power and draws dust and dirt into the equipment. I also believe that a fan that runs only during PTT is not doing much good except on very long transmissions- when the heat of the PA has made it to the fins. It may take several minutes of key-down time before the fins start getting warm, so running the fan before then is ineffective. My practice is to fix a normally-open thermal switch to one of the heat-sink fins, using heat-sink compound for good heat transfer. I have found that a switch that closes at 122 degrees Fahrenheit (50 degrees Celsius) works best, since it opens about ten degrees lower, and provides near-ideal hysteresis. The thermal switch directly controls a small AC or DC fan that blows on the fins. Not only is this an extremely simple solution, but it ensures that the fan will run only when needed and for as long as needed. I use a Cantherm switch that Digi-Key sells under catalog number 317- 1094-ND for about $7. 73, Eric Lemmon WB6FLY --- In Repeater-Builder@yahoogroups.com, Chuck Kelsey wb2...@... wrote: Maybe it's just me, but I've never understood the need for a special circuit to run cooling fans. I run my fans from the PTT line using a relay. I have also used a simple chassis thermostat, but prefer using PTT. I suppose you could easily use both methods so that in the event that the equipment remained too warm when PTT halts, the thermostat could keep it running longer. However, I contend that if this is happening, your fans are inadequate and not keeping up with the demand right along. Why the need to continue cooling after the QSO has ended? Just because you can? Chuck WB2EDV - Original Message - From: skipp025 skipp...@... To: Repeater-Builder@yahoogroups.com Sent: Sunday, December 21, 2008 12:24 PM Subject: [Repeater-Builder] Re: fan timer circuit Re: fan timer circuit I've seen a number of fan delay, time on, time off circuits posted on web. The neat'o web page url I just posted here on the group has one and it might be the one you're looking for. http://www.w1ghz.org/small_proj/small_proj.htm and the fan controller information is about half way down the page with a picture and down-loadable zip file. My own personal preference is to run everything warm and even a lot higher temp than most of you would expect. In a repeater station operation only an RF PA and un-modified Astron Power Supply with an undersized heat sink might get a fan. Never a failure of a well planned installation. Some of our local start-up radio clubs throwing repeater packages in place often start out using and stay with an external RF amplifier designed for mobile operation. Sometimes the amp runs so hot you can't keep your hand on the heat sink but I've yet to see one fail. cheers, skipp
Re: [Repeater-Builder] Re: fan timer circuit
I moved over to utilizing the PTT instead of the thermostat disks after I'd had a few thermostats fail. But I agree with your thinking. In my mind the slight inefficiency of running my fans earlier than the heat builds up is not significant to me. I like to think it slows the heat buildup. Once everything reaches a stable temperature and the repeater goes idle, there is no new heat generated and things cool more gradually without the fan blowing. But this is nit-picking. Either way works fine without adding unnecessary circuitry. Chuck WB2EDV - Original Message - From: wb6fly wb6...@verizon.net To: Repeater-Builder@yahoogroups.com Sent: Sunday, December 21, 2008 4:27 PM Subject: [Repeater-Builder] Re: fan timer circuit I mostly agree. My thinking is that a fan that runs continuously wastes power and draws dust and dirt into the equipment. I also believe that a fan that runs only during PTT is not doing much good except on very long transmissions- when the heat of the PA has made it to the fins. It may take several minutes of key-down time before the fins start getting warm, so running the fan before then is ineffective. My practice is to fix a normally-open thermal switch to one of the heat-sink fins, using heat-sink compound for good heat transfer. I have found that a switch that closes at 122 degrees Fahrenheit (50 degrees Celsius) works best, since it opens about ten degrees lower, and provides near-ideal hysteresis. The thermal switch directly controls a small AC or DC fan that blows on the fins. Not only is this an extremely simple solution, but it ensures that the fan will run only when needed and for as long as needed. I use a Cantherm switch that Digi-Key sells under catalog number 317- 1094-ND for about $7. 73, Eric Lemmon WB6FLY
Re: [Repeater-Builder] fan timer circuit
The thermal switches sold for attic fans should work great. I bought one rated at 119ºF at a surplus store. My S-COM controllers all had start-of-activity and end-of-activity macro triggers, which would be a more elegant way to do the timer-based function than a separate board with a 555 IC. Personal opinion, but I'd never put up a repeater that relied on a fan to keep temps within spec. I remember being horrified when Icom repeaters went to using a single internal fan with no air filter blowing through both the PA and power supply heatsinks, with the air exiting through a vent hole in the back. I much preferred the older style with the full-width cast-aluminum sink. 73, Paul, AE4KR - Original Message - From: Michael Ryan To: Repeater-Builder@yahoogroups.com Sent: Saturday, December 20, 2008 11:57 AM Subject: [Repeater-Builder] fan timer circuit I was directed by someone on the reflector here some months back, to a cooling fan timer circuit that is posted on the repeater builders website. I wonder if anyone has tried to build this ? - Thanks.. - Mike
Re: [Repeater-Builder] Re: fan timer circuit
One Summer's day in Los Angeles I had a service call on a microwave repeater (vacuum tube). It was located in a warehouse, near the roof. In the heat I lugged my stuff up the stairs. As I set down the service monitor I leaned my other arm against the cabinet. I jerked it away because it was burning my forearm. I was impressed that the equipment would operate at those temperatures; but I'm sure that the MTBF was reduced. Mike - AA8K n...@no6b.com wrote: 70 °C, the upper operating temperature limit of many RF devices, is too hot to touch. However, MTBF will definitely be reduced. In addition, without better cooling the devices board will experience greater temperature extremes, which would result in more failures caused by thermal cycling.
RE: [Repeater-Builder] Re: Motorola Duplexer Info Needed
There you go Joe! The man with all the answers! That sounds like the exact situation you have! Good work on that info! Now I'll have to go back and see what the deal was with the duplexer we had here! Bill - W6CBS _ From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of nj902 Sent: Wednesday, December 03, 2008 2:02 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Motorola Duplexer Info Needed The technical data for the UHF MSR2000 duplexers is contained in a section of the UHF station manual, 68-81061E55, behind the OPTIONS tab. This section was not included in the original -O release of the manual but is definitely in newer manuals such as the -C version. The MSR2000 duplexer family consists of several 2 and 4 cavity models covering the frequency range from 406-520 MHz. The same TRN9041A cavities are used in all of the models, thus the mechanical construction of the cavities should not be a factor in your issue. Different antenna and interconnect cable sets are used for each of the three frequency ranges: 406-430 MHz, 430-470 MHz, and 470-520 MHz. The 4 cavity T4085A models operate at T-R spacings of greater than 3 MHz whereas the T5002A models are configured for separations between 2 and 3 MHz. These use a different set of coupling loops than the T4085A. The maximum input power specification for these duplexers is 250 Watts. -- --- In Repeater-Builder@ mailto:Repeater-Builder%40yahoogroups.com yahoogroups.com, Joe Burkleo joeburk...@... wrote: I have a Motorola 4 can duplexer out of a UHF MSR2000 series radio that is the pass/notch style. ... I can not find any info on this unit ...
RE: [Repeater-Builder] make some extram money (Repair Job)
Joe, Sent you an email off list and it bounced. Shoot me an email. Commconinc @ Gmail.com Thanks Peter -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Joe Sent: Tuesday, December 02, 2008 8:11 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] make some extram money (Repair Job) Is anyone intrested in making some extra money.I have to motorola raduis, one VHF and a UHF and the cross band does not work...I am willing to pay some one to fix it. Please contact Joe at joen5...@bellouth. mailto:Joen5ozg%40bellouth.net net
RE: [Repeater-Builder] Manual needed Motorola S-1320A Signal Generator
Arthur, I don't have a copy of the manual, but I can advise you that the manual part number is 68-81061A75, which may help you find a copy. Unfortunately, it is NLA from Motorola Parts. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Arthur R Carlson Sent: Saturday, December 06, 2008 5:34 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Manual needed Motorola S-1320A Signal Generator I have 2 Motorola S-1320A-1 Solid state signal generators in my shop that I need to service. One has intermitant 1000hz tone sometimes it works and usually when you need it it doesn't. The other has a power supply problem. I would like to find a manual for this either borrow, rent or buy. I use it for repeater site work and it takes a beating but I can't afford to upgrade right now. Does someone out there have a manual on the shelf that would be willing to assist. Thanks Art. Can respond off list to wa0...@hotmail.com mailto:wa0njr%40hotmail.com
[Repeater-Builder] Couple radio questions
Hello group. Not specifically repeater questions, but thought this group might hold the folks who have the answers... I have a Motorola Spectra VHF High Power (110 watts) that I am converting for packet use, as an APRS digi-peater. It will be a high-profile machine...probably running around 30-40% TX duty cycle...possibly more during certain times. My first question is about cooling. It, along with a 35 amp power supply, will be located in a gutted Motorola repeater cabinet, which has 4 large ventilation grills on each door (2)...should I be concerned with supplemental cooling? And second, anybody have any information on how to go about adding an S-meter to the Spectra? 73, and happy holidays. _ Chris Greenhalgh, N8WCT www.n8wct.com http://www.n8wct.com/
Re: [Repeater-Builder] Re: fan timer circuit
Sounds like the best thing to do is a combination of both the PTT and Thermodisk versions together. That way the fan starts blowing when users start using the repeater. Then the thermodisk takes over after it heats up until all traffic quits and the tx'er cools down. Just my 2c worth. Merry Christmas everybody!! Mike
Re: [Repeater-Builder] Converting a Range 2 VHF Mitrek to Range 1 (WAS: Holiday Special...)
GOOD AFTERNOON kEVIN This last response is my thinking about the Mitrek and is why I asked the question earlier. If the Mitrek coils are the same as the Micor coils what factor would prohibit this being done. There is considerable work to change the coils but if the Micor coils are the same nothing would prohit a person from doing this. As I said earlier I know for a fact that the mid band receivers will not tune lower than 146 Mhz. Perhaps an occasional one would be found that would tune to 144.0 Mhz but not all. Thanks. 73 de Tom Manning, AF4UG - Original Message - From: Gmail - Kevin, Natalia, Stacey Rochelle To: Repeater-Builder@yahoogroups.com Sent: Sunday, December 21, 2008 12:54 AM Subject: Re: [Repeater-Builder] Converting a Range 2 VHF Mitrek to Range 1 (WAS: Holiday Special...) Hi, Is there a point inside the Mitrek that one can take the audio out to the controller (in this case a Link-Comm RLC-2A)? A low band Mitrek (33Mhz) I have downloaded the information fromLou's Mitrek Repeater Conversion and a couple of others which mention a schematic for emphasis before going into the controller. Taking the audio out on pin 11. I would like to leave this out if possible and feed directly? Regards and Merry Christmas Kev. - Original Message - From: Kevin Custer To: Repeater-Builder@yahoogroups.com Sent: Sunday, December 21, 2008 2:40 PM Subject: Re: [Repeater-Builder] Converting a Range 2 VHF Mitrek to Range 1 (WAS: Holiday Special...) Eric Lemmon wrote: Only one of the five front-end coils for a Range 1 VHF Mitrek (HLD4081, 136-146 MHz) is still available from Motorola Parts. That one is part 2480032A07, the violet coil in L1, for $ 4.15. The only option may be to tack on some extra wire to the existing coils. Although modifying the tuning screws may work, I suspect the Q will suffer. Eric, I would think a coil retro like what I make available for the MICOR will also work in the Mitrek. This approach would be way better than tacking some added wire onto the existing coil or modifying the screws in which I know that is a bad idea. Is there something special about the Mitrek front-end that you believe would prohibit such a conversion? It's been a while since I messed with the Mitrek but I don't remember anything that would prohibit the correct length coil to be installed... Kevin -- I am using the free version of SPAMfighter. We are a community of 5.7 million users fighting spam. SPAMfighter has removed 1561 of my spam emails to date. Get the free SPAMfighter here: http://www.spamfighter.com/len The Professional version does not have this message
Re: [Repeater-Builder] Converting a Range 2 VHF Mitrek to Range 1 (WAS: Holiday Special...)
Hello Kevin I did not see where you gave a price of a set of Micor receiver coils. Where might I find this info? Thanks. 73 de Tom Manning, AF4UG - Original Message - From: Eric Lemmon To: Repeater-Builder@yahoogroups.com Sent: Saturday, December 20, 2008 9:37 PM Subject: RE: [Repeater-Builder] Converting a Range 2 VHF Mitrek to Range 1 (WAS: Holiday Special...) Kevin, Other than being physically smaller, I don't know of any helical resonator design issues that preclude your Micor mod from being adapted to the Mitrek. I am modifying some low-band Mitreks for 6m duty, but all that takes is a handful of capacitors. I have yet to address converting a high-band Mitrek to 2m, so I have no idea what issues may arise. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Kevin Custer Sent: Saturday, December 20, 2008 5:41 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Converting a Range 2 VHF Mitrek to Range 1 (WAS: Holiday Special...) Eric Lemmon wrote: Only one of the five front-end coils for a Range 1 VHF Mitrek (HLD4081, 136-146 MHz) is still available from Motorola Parts. That one is part 2480032A07, the violet coil in L1, for $ 4.15. The only option may be to tack on some extra wire to the existing coils. Although modifying the tuning screws may work, I suspect the Q will suffer. Eric, I would think a coil retro like what I make available for the MICOR will also work in the Mitrek. This approach would be way better than tacking some added wire onto the existing coil or modifying the screws in which I know that is a bad idea. Is there something special about the Mitrek front-end that you believe would prohibit such a conversion? It's been a while since I messed with the Mitrek but I don't remember anything that would prohibit the correct length coil to be installed... Kevin -- I am using the free version of SPAMfighter. We are a community of 5.7 million users fighting spam. SPAMfighter has removed 1561 of my spam emails to date. Get the free SPAMfighter here: http://www.spamfighter.com/len The Professional version does not have this message
Re: [Repeater-Builder] Couple radio questions
On Sun, 21 Dec 2008, Christopher K. Greenhalgh wrote: It will be a high-profile machine...probably running around 30-40% TX duty cycle...possibly more during certain times. Well, you're out of what the manual specifies the duty cycle of the radio to be. Accordingly, you should look at turning the transmitter power down to extend the service life of the radio. My first question is about cooling. It, along with a 35 amp power supply, will be located in a gutted Motorola repeater cabinet, which has 4 large ventilation grills on each door (2)...should I be concerned with supplemental cooling? I mounted two 1/2 5 fans on two of the windows of the mid-size base cabinet. That being said, our repeater presently has a duty cycle of 1%. But we're also in an air-conditioned space -- is your digipeater going to be located in a similar space, or is it at whatever temperature the room is at (-40 or 140 degrees F)? If the Spectra is close to the rating of the Syntor X9000, you should be able to turn the PA down to 55 watts and let it run. However, the X9000 has the notable distinction of having approximately 35 watts of heatsink area, and only the 30/50 watt radios can be run at 100% duty cycle (assuming no further derating due to elevated room temperatures). And second, anybody have any information on how to go about adding an S-meter to the Spectra? Get a manual. =) There's some way through hacking to enable an RSSI function on the Spectra, but IIRC it doesn't work in a non-trunking mode and requires very specific firmware in the radio (MLM). But that also assumes that you want to view RSSI at the radio's control head, not remotely. -- Kris Kirby, KE4AHR k...@catonic.us But remember, with no superpowers comes no responsibility. --rly
RE: [Repeater-Builder] Converting a Range 2 VHF Mitrek to Range 1 (WAS: Holiday Special...)
Tom, The Mitrek coils are not the same as Micor coils. Not even close. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Tom Manning Sent: Sunday, December 21, 2008 3:40 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Converting a Range 2 VHF Mitrek to Range 1 (WAS: Holiday Special...) GOOD AFTERNOON kEVIN This last response is my thinking about the Mitrek and is why I asked the question earlier. If the Mitrek coils are the same as the Micor coils what factor would prohibit this being done. There is considerable work to change the coils but if the Micor coils are the same nothing would prohit a person from doing this. As I said earlier I know for a fact that the mid band receivers will not tune lower than 146 Mhz. Perhaps an occasional one would be found that would tune to 144.0 Mhz but not all. Thanks. 73 de Tom Manning, AF4UG - Original Message - From: Gmail - Kevin, Natalia, Stacey Rochelle mailto:spar...@gmail.com To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder@yahoogroups.com Sent: Sunday, December 21, 2008 12:54 AM Subject: Re: [Repeater-Builder] Converting a Range 2 VHF Mitrek to Range 1 (WAS: Holiday Special...) Hi, Is there a point inside the Mitrek that one can take the audio out to the controller (in this case a Link-Comm RLC-2A)? A low band Mitrek (33Mhz) I have downloaded the information fromLou's Mitrek Repeater Conversion and a couple of others which mention a schematic for emphasis before going into the controller. Taking the audio out on pin 11. I would like to leave this out if possible and feed directly? Regards and Merry Christmas Kev. - Original Message - From: Kevin Custer mailto:kug...@kuggie.com To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder@yahoogroups.com Sent: Sunday, December 21, 2008 2:40 PM Subject: Re: [Repeater-Builder] Converting a Range 2 VHF Mitrek to Range 1 (WAS: Holiday Special...) Eric Lemmon wrote: Only one of the five front-end coils for a Range 1 VHF Mitrek (HLD4081, 136-146 MHz) is still available from Motorola Parts. That one is part 2480032A07, the violet coil in L1, for $ 4.15. The only option may be to tack on some extra wire to the existing coils. Although modifying the tuning screws may work, I suspect the Q will suffer. Eric, I would think a coil retro like what I make available for the MICOR will also work in the Mitrek. This approach would be way better than tacking some added wire onto the existing coil or modifying the screws in which I know that is a bad idea. Is there something special about the Mitrek front-end that you believe would prohibit such a conversion? It's been a while since I messed with the Mitrek but I don't remember anything that would prohibit the correct length coil to be installed... Kevin I am using the Free version of SPAMfighter http://www.spamfighter.com/len We are a community of 5.7 million users fighting spam. SPAMfighter has removed 1561 of my spam emails to date. The Professional version does not have this message
[Repeater-Builder] OT: Radios and Coms in TV and Movies
I was wondering if anyone had links to any websites that talk about radios used in TV and Movies. What got me thinking about this was that I had been watching the old TV show Emergency on Netflix. (remember squad 51, rampart hospital, etc.) I know some of the stuff is just props but I thought some of it might be real equipment that I don't recognize. For instance one of the characters (Roy) often carries an HT into the hospital when they drop off a patient. I think it is an HT220 since it has a telescoping antenna, but might be a MT500. Thanks
Re: [Repeater-Builder] OT: Radios and Coms in TV and Movies
You can start here... http://www.emergencyfans.com/ Eric, VA3EAM Albert wrote: I was wondering if anyone had links to any websites that talk about radios used in TV and Movies. What got me thinking about this was that I had been watching the old TV show Emergency on Netflix. (remember squad 51, rampart hospital, etc.) I know some of the stuff is just props but I thought some of it might be real equipment that I don't recognize. For instance one of the characters (Roy) often carries an HT into the hospital when they drop off a patient. I think it is an HT220 since it has a telescoping antenna, but might be a MT500. Thanks
RE: [Repeater-Builder] OT: Radios and Coms in TV and Movies
Albert, If you do find such a site, let me know! I was watching the Bruce Willis flick Live Free or Die Hard and noticed that every government agency and the DC Police used an ADI AR-147 2m mobile radio in their cars. I guess interoperability has finally taken hold, because every radio in the movie was displaying 144.330 MHz! Geez- you'd think that someone on the movie staff could do better than that... 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Albert Sent: Sunday, December 21, 2008 4:33 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] OT: Radios and Coms in TV and Movies I was wondering if anyone had links to any websites that talk about radios used in TV and Movies. What got me thinking about this was that I had been watching the old TV show Emergency on Netflix. (remember squad 51, rampart hospital, etc.) I know some of the stuff is just props but I thought some of it might be real equipment that I don't recognize. For instance one of the characters (Roy) often carries an HT into the hospital when they drop off a patient. I think it is an HT220 since it has a telescoping antenna, but might be a MT500. Thanks
Re: [Repeater-Builder] Converting a Range 2 VHF Mitrek to Range 1 (WAS: Holiday Special...)
Tom Manning wrote: GOOD AFTERNOON kEVIN This last response is my thinking about the Mitrek and is why I asked the question earlier. If the Mitrek coils are the same as the Micor coils what factor would prohibit this being done. The coils are not the same, but I believe there is no reason I wouldn't be able to reproduce coils that would replicate the factory low split ones for the Mitrek. There is considerable work to change the coils but if the Micor coils are the same nothing would prohit a person from doing this. As I said earlier I know for a fact that the mid band receivers will not tune lower than 146 Mhz. Perhaps an occasional one would be found that would tune to 144.0 Mhz but not all. Thanks. 73 de Tom Manning, AF4UG I need to look at a VHF Mitrek and see if I can build replacements and at what cost. I did not see where you gave a price of a set of Micor receiver coils. Where might I find this info? Thanks. 73 de Tom Manning, AF4UG The Holiday Special price of the VHF MICOR redo is laid out in the link below: http://www.repeater-builder.com/rbtip/hs-coilinstructions.html Kevin
Re: [Repeater-Builder] Re: fan timer circuit
At 12/21/2008 14:01, you wrote: I moved over to utilizing the PTT instead of the thermostat disks after I'd had a few thermostats fail. But I agree with your thinking. My thoughts as well: the thermostat is an elegant solution, but if it fails, your repeater fails in a rather expensive way. One reason why I've dismissed using any switching on my 110 V cooling fans let them spin 24/7. The 12 V fans get switched by PTT, though I use a separate buffer transistor to key them. Otherwise the fan motor dumps noise onto the PTT line, which finds its way into the TX audio. You could wire two thermostats in parallel so if one opens up you don't lose cooling. However, to be an effective safeguard against failure they should be independently tested when doing your PM. Bob NO6B
Re: [Repeater-Builder] fan timer circuit
At 12/21/2008 14:15, you wrote: Personal opinion, but I'd never put up a repeater that relied on a fan to keep temps within spec. Yes, fans are not as reliable as 100% passive cooling. Unfortunately, the latter method requires a lot more rack real estate which sometimes ( in my case, always) isn't available. Bob NO6B
Re: [Repeater-Builder] Re: fan timer circuit
n...@no6b.com wrote: One reason why I've dismissed using any switching on my 110 V cooling fans let them spin 24/7. I have used 220 V muffin fans on 110 V and they last for years. I put one in service in 1997, and it's still turning. Kevin
Re: [Repeater-Builder] Re: fan timer circuit
Kevin, another method of slowing down an AC fan is to put a capacitor in series with the AC leads as a voltage dropping element. A local Ham played with this idea many years ago and as I recall he started with a 1 Mfd paper capacitor. In his case he dropped the voltage to around 90 volts to the fan. 73 John VE3AMZ - Original Message - From: Kevin Custer To: Repeater-Builder@yahoogroups.com Sent: Sunday, December 21, 2008 8:58 PM Subject: Re: [Repeater-Builder] Re: fan timer circuit n...@no6b.com wrote: One reason why I've dismissed using any switching on my 110 V cooling fans let them spin 24/7. I have used 220 V muffin fans on 110 V and they last for years. I put one in service in 1997, and it's still turning. Kevin
Re: [Repeater-Builder] NHRC-Squelch Board
Jordan, The RLC-MOT works very well since it is an exact copy of the squelch circuit found in the Micor. The only problem is it is now VERY expensive. Kevin had done some extensive testing on the dual squelch modues some time ago. Maybe he can chime in here... Kev?? Scott Scott Zimmerman Amateur Radio Call N3XCC 474 Barnett Road Boswell, PA 15531 - Original Message - From: twoway_tech jcar...@k9nzf.com To: Repeater-Builder@yahoogroups.com Sent: Friday, December 19, 2008 7:20 PM Subject: [Repeater-Builder] NHRC-Squelch Board Anybody have any NHRC-squelch boards in service? I am looking at getting either one of those or a RLC-MOT board from link Communications. Is one better then the other? Do they do the same thing? Anybody try to clone an NHRC board? (they look easy) I am wanting to install something on a Mitrek for that nice Micor type squelch. Actually, I just want to get rid of that Chkccc! Thanks, Jordan Yahoo! Groups Links No virus found in this incoming message. Checked by AVG - http://www.avg.com Version: 8.0.176 / Virus Database: 270.9.19/1857 - Release Date: 12/19/2008 10:09 AM
Re: [Repeater-Builder] Re: fan timer circuit
One more thing to be careful of when using fans on remote equipment. Make sure there are guards on both sides of the fan. We had a muffin fan on a 100wt 220 amp that failed when a mouse tried to get closer to the warm heatsink. His carcass jammed the fan blades and got dessicated with the heat. Burt Lang VE2BMQ
RE: [Repeater-Builder] Re: fan timer circuit
m... From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Burt Lang Sent: Sunday, December 21, 2008 10:39 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Re: fan timer circuit One more thing to be careful of when using fans on remote equipment. Make sure there are guards on both sides of the fan. We had a muffin fan on a 100wt 220 amp that failed when a mouse tried to get closer to the warm heatsink. His carcass jammed the fan blades and got dessicated with the heat. Burt Lang VE2BMQ __ NOD32 3709 (20081220) Information __ This message was checked by NOD32 antivirus system. http://www.eset.com
[Repeater-Builder] Rat Track Solvent?
Hello All I said OK to an invitation to fix a repeater that suddenly quit after years of trouble free service. Found a critical wire chewed in two and several more almosts. The fixes were easy but a problem remains in the cleanup. Rat trash and droppings (OK to read as a common four letter word) swept and vacuumed out easily but the brown tracking residue remaining on the base surfaces and trails is resistant to everything I have triedwater, dish and laundry detergents straight and with water, 409, alcohol, Goo-off and paint thinner. The crud releases from vinyl wire with a lot of scrubbing using one of the detergents and water but nothing I have tried lifts the crud at all from a painted, galvanized or plated metal surface. What works?---any and all practical suggestions will be tried and their performance reported. Thanks much-- Scott, N6NXI
RE: [Repeater-Builder] Re: fan timer circuit
a mouse tried to get closer to the warm heatsink. His carcass jammed the fan blades and got dessicated with the heat. Burt Lang VE2BMQ Yes I guess that could Happen , I live in a City and My 6 Month old Fridge quit working , Well of Course bring a Ham Some of us including Me thing We can fix anything , I pulled it out from the wall and Found a Dead Mouse caught up in the Fan blade stopping it . I dug it out and cleaned it out put a screen over it, Plugged it in and it has been working great now for a couple of years. My Wife likes to use Decon , I understand the Mice swell up and look for water then go behind the walls etc and Decay and smell . So it was all Her fault Happy Holidays Don
RE: [Repeater-Builder] Rat Track Solvent?
Pretty hard to remove , I have in the past had some success with crc inox and several other derusting thread lubricants ( sorry don't know the local names in your part of the world) Most of them contain mineral turpentine and some other oils which offer the chance of at least softening that stuff. To: Repeater-Builder@yahoogroups.com CC: sc...@becklawfirm.com From: sc...@becklawfirm.com Date: Sun, 21 Dec 2008 21:20:54 -0800 Subject: [Repeater-Builder] Rat Track Solvent? Hello All I said OK to an invitation to fix a repeater that suddenly quit after years of trouble free service. Found a critical wire chewed in two and several more almosts. The fixes were easy but a problem remains in the cleanup. Rat trash and droppings (OK to read as a common four letter word) swept and vacuumed out easily but the brown tracking residue remaining on the base surfaces and trails is resistant to everything I have triedwater, dish and laundry detergents straight and with water, 409, alcohol, Goo-off and paint thinner. The crud releases from vinyl wire with a lot of scrubbing using one of the detergents and water but nothing I have tried lifts the crud at all from a painted, galvanized or plated metal surface. What works?---any and all practical suggestions will be tried and their performance reported. Thanks much-- Scott, N6NXI _ Messenger's gift to you! Download free emoticons today! http://livelife.ninemsn.com.au/article.aspx?id=669758
Re: [Repeater-Builder] Rat Track Solvent?
Whatever you do, use caution in cleaning that stuff up. Rodent droppings, especially when they become dried over time, are a major threat to carry some really vicious diseases into your body if the dust gets airborne. http://www.cdc.gov/rodents/diseases/direct_rodents.htm 73, Paul, AE4KR - Original Message - From: Scott To: Repeater-Builder@yahoogroups.com Cc: Scott Overstreet Sent: Sunday, December 21, 2008 10:20 PM Subject: [Repeater-Builder] Rat Track Solvent? Hello All I said OK to an invitation to fix a repeater that suddenly quit after years of trouble free service. Found a critical wire chewed in two and several more almosts. The fixes were easy but a problem remains in the cleanup. Rat trash and droppings (OK to read as a common four letter word) swept and vacuumed out easily but the brown tracking residue remaining on the base surfaces and trails is resistant to everything I have triedwater, dish and laundry detergents straight and with water, 409, alcohol, Goo-off and paint thinner. The crud releases from vinyl wire with a lot of scrubbing using one of the detergents and water but nothing I have tried lifts the crud at all from a painted, galvanized or plated metal surface. What works?---any and all practical suggestions will be tried and their performance reported. Thanks much-- Scott, N6NXI
