Re: [Repeater-Builder] Problem with fan noise in power line.
I would suggest you try a 100uH inductor and as well as a 1000uF capacitor as an L/C filter. You may need 2 sets in series depending on how bad the noise is. On 4/17/07, Doug Hutchison [EMAIL PROTECTED] wrote: Have a system comprising 4m simplex link and 2m repeater running from same PSU. Tried using a brushless fan to boost cooling but when running and connected on the same PSU as the RF kit, the noise generated on 4m TX audio (not 2m), a very loud buzz, is incredible. Obviously the inverter noise is being carried back into the PSU so some sort of filtering is needed as, when the fan is run on a separate supply, there is no problem. Has anyone encountered such a situation and if so what circuit or device was used to cure the noise (other that a second PSU)? Regards, Doug - GM7SVK Yahoo! Groups Links
Re: [Repeater-Builder] Rethinking the Possible poll question
Jim, Right now we have a very good relationship with the building owner and the transmitter in there. Our space rent is very nominal and I want to keep it that way. I thinking of trying to hang a rack on the wall that will give us VHF and UHF in the same cabinet, if possible. Our system is located where a person can not walk around the other equipment in the building. They have not complained and I thought it would be a good idea to try and allow at least that much. Bob Smith WB6ODR, Prescott, AZ - Original Message - From: Jim B. [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Monday, April 16, 2007 10:21 AM Subject: Re: [Repeater-Builder] Rethinking the Possible poll question Bob Linda Smith wrote: Dear Chuck and everyone else who gave valuable suggestions, It looks like I, and the club, need to rethink this question. I am very impressed with some of the new equipment out there and was thinking our radio is a bit outdated. Also, I was thinking of the space we occupy in our shared building. Thinking a smaller foot print could be hung on the wall easily. Unless you're being told to shrink your footprint in the building, I wouldn't voluntarily do it. Now, making the package smaller so you can fit in other stuff, well, that's different ;c} -- Jim Barbour WD8CHL Yahoo! Groups Links
Re: [Repeater-Builder] Re: Opening Salvo Poor Mans Repeater Project
I'm sorry. I should have been more clear on my first post. This repeater was being built for GMRS NOT FRS. The FRS radio I was using has a trim cap on the crystal for the PLL allowing it to be tuned to the GMRS frequencies. This radio is for receive only. The PTT button has been removed. It has also been modded to accept an external antenna. No transmit = no type acceptance issue. --- Jim B. [EMAIL PROTECTED] wrote: rtoplus wrote: My only response on this topic since Kevin doesn't allow rules discussions. GMRS is allowed up to 50 watts TPO unless you are operating a small base station, then the 15 watt rule comes into play. A small base station operates at 5ppm minimum frequency tolerance and a standard base station or repeater must maintain minimum of 2.5ppm. A small base station also has height restrictions. I was referring to the FRS channels. -- Jim Barbour WD8CHL __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
Re: [Repeater-Builder] Re: Poor Mans Repeater - Receiver
- Original Message - From: skipp025 [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Monday, April 16, 2007 12:33 PM Subject: [Repeater-Builder] Re: Poor Mans Repeater - Receiver Voice ID would be legal. If the regs read the same for the repeater... the legal ID is required once at the end of the standard 10 min talk period. cheers, s. I have seen several references, both here and on another Yahoo group, about users ID'ing for a ham repeater. I know Kevin doesn't allow rules discussions here, so perhaps someone can explain to me off-list just HOW any part of 97.119, and in particular, 97.119(a), can be interpreted to allow one amateur station (the user) to ID for another (the repeater) George, KA3HSW / WQGJ413
[Repeater-Builder] Re:Label makers
Kroy makes a compact labeler that prints on heat-shrink tubing. I also use Brother P-Touch labels under clear heat-shrink. Actually, almost anything under clear heat-shrink works. I've had mixed results with the 'self-laminating' kinds. Unless you use a stable ink (NOT sharpie), they tend to bleed and spread over time, eventually becoming unreadable after about 5 years. Panduit makes a pen specifically for marking nylon. Staedtler also makes some nice pens. -Cam.
[Repeater-Builder] Yaesu FT4700H for cross band repeater operation.
Hi, any one help me with conversion details for the yaesu FT-4000H for cross band repeater operating mode. regards deepan Vu2 dpn _ Palate teasers: Straight from Master Chef Sanjeev Kapoor http://content.msn.co.in/Lifestyle/Moreonlifestyle/LifestylePT_101106_1530.htm
[Repeater-Builder] Thanks for the info
Thanks Nate, I've put your email in the special folder on our repeater.. I remember when I was with the Phone Co., we did just what you are suggesting.. Wrote it all down, twice or three times, that was before digital photos of course.. 73, Bob Smith WB6ODR, Prescott, AZ - Original Message - From: Nate Duehr To: Repeater-Builder@yahoogroups.com Sent: Monday, April 16, 2007 4:24 PM Subject: Re: [Repeater-Builder] Rethinking the Possible poll question On 4/15/07, Bob Linda Smith [EMAIL PROTECTED] wrote: I think our Micor must have been properly converted because it has been on the air for about 25 years according to the original owner who I talk with 2 weeks ago. Our Micro is on 2 meters and has a 70 cm receiver in the cabinet who's frequency I don't know. Need to find that out!! The main reason for a possible change of equipment is the possibility of some digital work later on. Thanks for the pointers. Bob WB6ODR Side note for your project there Bob, Just because it was on-air doesn't mean it performed well, or even to spec. If you have things like a UHF receiver in the cabinet that you don't know what it is, now is the time to document, document, document... Later on, you'll certainly want to know things like, Just where is that wire from the controller hooked to, and digital photos, drawings of all wiring, etc... are what you'll need. Attack the thing with a label maker too, and label every cable interconnect and every port they plug into. Take lots of pictures. Go nuts. Digital is cheap. Next, find someone with the right test gear and measure all the basics as it's installed at your site. Receiver sensitivity off and on the antenna system, transmitter power level, duplexer isolation, feedline losses... whatever you can measure, and write it all down somewhere -- start your engineering book for the repeater system, and then require that if changes are made, the docs get updated. You'll be happy you did later. And as friends say, if you haven't measured -- you don't know where you're starting from... Nate WY0X
[Repeater-Builder] Problem with fan noise in power line.
Have a system comprising 4m simplex link and 2m repeater running from same PSU. Tried using a brushless fan to boost cooling but when running and connected on the same PSU as the RF kit, the noise generated on 4m TX audio (not 2m), a very loud buzz, is incredible. Obviously the inverter noise is being carried back into the PSU so some sort of filtering is needed as, when the fan is run on a separate supply, there is no problem. Has anyone encountered such a situation and if so what circuit or device was used to cure the noise (other that a second PSU)? Regards, Doug - GM7SVK
RE: [Repeater-Builder] Thanks for the info
Our Micro is on 2 meters and has a 70 cm receiver in the cabinet who's frequency I don't know. Need to find that out!! ^ control receiver maybe??? just a thought... 73 Mike Perryman www.k5jmp.us -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] Behalf Of Bob Linda Smith Sent: Monday, April 16, 2007 8:47 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Thanks for the info Thanks Nate, I've put your email in the special folder on our repeater.. I remember when I was with the Phone Co., we did just what you are suggesting.. Wrote it all down, twice or three times, that was before digital photos of course.. 73, Bob Smith WB6ODR, Prescott, AZ - Original Message - From: Nate Duehr To: Repeater-Builder@yahoogroups.com Sent: Monday, April 16, 2007 4:24 PM Subject: Re: [Repeater-Builder] Rethinking the Possible poll question On 4/15/07, Bob Linda Smith [EMAIL PROTECTED] wrote: I think our Micor must have been properly converted because it has been on the air for about 25 years according to the original owner who I talk with 2 weeks ago. Our Micro is on 2 meters and has a 70 cm receiver in the cabinet who's frequency I don't know. Need to find that out!! The main reason for a possible change of equipment is the possibility of some digital work later on. Thanks for the pointers. Bob WB6ODR Side note for your project there Bob, Just because it was on-air doesn't mean it performed well, or even to spec. If you have things like a UHF receiver in the cabinet that you don't know what it is, now is the time to document, document, document... Later on, you'll certainly want to know things like, Just where is that wire from the controller hooked to, and digital photos, drawings of all wiring, etc... are what you'll need. Attack the thing with a label maker too, and label every cable interconnect and every port they plug into. Take lots of pictures. Go nuts. Digital is cheap. Next, find someone with the right test gear and measure all the basics as it's installed at your site. Receiver sensitivity off and on the antenna system, transmitter power level, duplexer isolation, feedline losses... whatever you can measure, and write it all down somewhere -- start your engineering book for the repeater system, and then require that if changes are made, the docs get updated. You'll be happy you did later. And as friends say, if you haven't measured -- you don't know where you're starting from... Nate WY0X
Re: [Repeater-Builder] New file uploaded to Repeater-Builder
At 4/16/2007 10:00 PM, you wrote: Good thinking Bob, I will look in to it. Do you have a schematic or the model number of the squelch you were working with? No schematic handy here. It was the stock squelch circuit in a mid-80's vintage Hamtronics R144 or whatever repeater grade RX they were selling at the time. The noise filter was a simple 2-pole BPF with a very high Q. The op amp they used was the dedicated op amp within the MC3357 or MC3359 IF amp/detector-on-a-chip. Nothing wrong with the op amp, just the circuit design around it. I would think ringing would be a problem with passive components Like L/C filters. But it may exist in a low quality op-amp that is not designed with a wide bandwidth. In this case the op amp isn't the problem, it's the overall circuit. I believe the LM324 series is only rated for 12kHz of bandwidth, the TL084 is about 3MHz. The unity gain BW of the LM324 is 1 MHz; the TL084 is 3 MHz. I wouldn't use either one much above audio frequencies. I am not even sure if I can simulate impulse noise. But in theory we can write a software algorithim to look for a patterned pulse and attempt to compenstate. Any decent SPICE simulator should be able to give you the transient response of your filter. Bob NO6B
Re: [Repeater-Builder] New file uploaded to Repeater-Builder
No schematic handy here. It was the stock squelch circuit in a mid-80's vintage Hamtronics R144 or whatever repeater grade RX they were selling at the time. The noise filter was a simple 2-pole BPF with a very high Q. The op amp they used was the dedicated op amp within the MC3357 or MC3359 IF amp/detector-on-a-chip. Nothing wrong with the op amp, just the circuit design around it. Roger. http://www.hamtronics.com/pdf/Manuals/R144-older.pdf may be what you were working with. A transistor for hysterieses just rases a number of suspicions. I learned to stop trusting built into IF chip squelch systems when I worked on a Regency repeater many moons ago. Any decent SPICE simulator should be able to give you the transient response of your filter. Multisim 6 is far from decent. It crashes more then it run. Subsequent versions are not any better. The entire Electronic workbench series is suspect.
[Repeater-Builder] mc-3357 mc-3359 squelch circuit
Re: mc-3357 mc-3359 squelch circuit Many receivers used the two mentioned chips... in both commericial, Amateur Radio and classic scanner circuits. I've seen both part numbers converted to tk numbers in Yaesu and Uniden Radios. There are a number of working squelch circuits using the back end section of the chip with and without external op amps. While the Hamtronics circuit is/was rather basic it did work pretty well and was easy to experiment with changes/mods. A faster pussycat version of the same circuit can be found in the Spectrum, some (if I remember right) older Maggiore or Melco and Icom Repeater Receiver circuits. External op amp sections were added as gain buffers and high speed switches to enhance the internal circuit operation. The Hamtronics transistor hysterisis circuit works ok so don't discount it as a bad design. The receiver is/was a very basic circuit and could be used in modest low power repeater operation without a lot of grief. If you really were interested in more work with the mentioned chips I can and would be happy to email you some circuit diagrams and manuals related to the chips used in quality well engineered designs/circuits (in pdf file format). As in our poor mans repeater project... sometimes when money is tight you try to use whatever you can get you hands on. cheers, skipp No schematic handy here. It was the stock squelch circuit in a mid-80's vintage Hamtronics R144 or whatever repeater grade RX they were selling at the time. The noise filter was a simple 2-pole BPF with a very high Q. The op amp they used was the dedicated op amp within the MC3357 or MC3359 IF amp detector-on-a-chip. Nothing wrong with the op amp, just the circuit design around it. Roger. http://www.hamtronics.com/pdf/Manuals/R144-older.pdf may be what you were working with. A transistor for hysterieses just rases a number of suspicions. I learned to stop trusting built into IF chip squelch systems when I worked on a Regency repeater many moons ago.
Re: [Repeater-Builder] mc-3357 mc-3359 squelch circui
Many receivers used the two mentioned chips... in both commericial, Amateur Radio and classic scanner circuits. I've seen both part numbers converted to tk numbers in Yaesu and Uniden Radios. I wanted to do a receiver based on the SA-604 and an external squelch circuit, but it is still on the projects list and it became hard to find a off the shelf 21.4MHz IF Quarature coil. If you really were interested in more work with the mentioned chips I can and would be happy to email you some circuit diagrams and manuals related to the chips used in quality well engineered designs/circuits (in pdf file format). I'd like that. As in our poor mans repeater project... sometimes when money is tight you try to use whatever you can get you hands on. If cheap is the goal why not just convert a MASTR-II or a Micor? The last 2 Micors I got were free and I paid $20 each for some Custom MVPs. Pretty cheap. I'd prefere designing something from the ground up vs. just converting something into the ham band.
Re: [Repeater-Builder] mc-3357 mc-3359 squelch circui
On 4/17/07, DCFluX [EMAIL PROTECTED] wrote: If cheap is the goal why not just convert a MASTR-II or a Micor? The last 2 Micors I got were free and I paid $20 each for some Custom MVPs. Pretty cheap. I'd prefere designing something from the ground up vs. just converting something into the ham band. I don't think cheap is the goal... or if it is... this project won't hit it. There's probably a jewel of truth hiding in your comments that could probably be summarized by this statement... Conversions are less expensive today than designing from the ground up. Additionally, the conversion will likely perform better... But, it remains to be seen if something that can rival the performance of a well-done conversion can come out of this new project at a cheaper price-point. I had two UHF GE MVP's handed to me for free once... hard to beat that price, if price is a serious factor. Nate WY0X
[Repeater-Builder] Re: mc-3357 mc-3359 squelch circuit (poor mans repeater receiver)
Nothing wrong with a Master II, Micor or MVP Radio. The test case radios I'm using for the poor mans repeater project are Midland Syntech 70-340b units, which cost us $10 each. Last night we put the previously built (by us) cor/cos interface relay (yes we used a relay vs something solid state) circuit into the radios(s). In addition to working as a repeater... this mod in two radios will also function as a bi-directional unit. Since the interface is universal to all the same radios... cross band port-hole operation is done by simply plugging two different band radios into the almost stock wire harness. There are simple provisions to lock the rx radio out from any tx during repeat receive cos/cor active. So we don't experience any repeater pumping during most linking or cross band operation. Mostly the modified radios will serve as receiver only units. The nice part about this conversion is how no mods need to be done to the tx radio. Yep... you read that right... More later on... cheers, skipp ps: I'll send you the information first thing in the morn... DCFluX [EMAIL PROTECTED] wrote: If cheap is the goal why not just convert a MASTR-II or a Micor? The last 2 Micors I got were free and I paid $20 each for some Custom MVPs. Pretty cheap. I'd prefere designing something from the ground up vs. just converting something into the ham band. Many receivers used the two mentioned chips... in both commericial, Amateur Radio and classic scanner circuits. I've seen both part numbers converted to tk numbers in Yaesu and Uniden Radios. I wanted to do a receiver based on the SA-604 and an external squelch circuit, but it is still on the projects list and it became hard to find a off the shelf 21.4MHz IF Quarature coil. If you really were interested in more work with the mentioned chips I can and would be happy to email you some circuit diagrams and manuals related to the chips used in quality well engineered designs/circuits (in pdf file format). I'd like that. As in our poor mans repeater project... sometimes when money is tight you try to use whatever you can get you hands on. If cheap is the goal why not just convert a MASTR-II or a Micor? The last 2 Micors I got were free and I paid $20 each for some Custom MVPs. Pretty cheap. I'd prefere designing something from the ground up vs. just converting something into the ham band.
Re: [Repeater-Builder] mc-3357 mc-3359 squelch circuit
A few years ago I designed a dual level squelch circuit that could be a replacement for the Micor type carrier squelch. I built a couple of the prototypes and put them into service, and they worked very well, you really couldn't tell them from the real thing. They were designed around readily available and cheap parts, so replicating it would be very easy. I think total parts costs would be around $5, not counting the board. If anyone is interested, I can supply a PDF of the schematic, or upload it to the site. Somewhere, I have some of the boards, but I don't remember exactly where they went. The schematic I have could probably be simplified even more, it was just an idea that I came up with, and it worked, so I didn't fool around with it anymore. Joe --- skipp025 [EMAIL PROTECTED] wrote: Re: mc-3357 mc-3359 squelch circuit Many receivers used the two mentioned chips... in both commericial, Amateur Radio and classic scanner circuits. I've seen both part numbers converted to tk numbers in Yaesu and Uniden Radios. There are a number of working squelch circuits using the back end section of the chip with and without external op amps. While the Hamtronics circuit is/was rather basic it did work pretty well and was easy to experiment with changes/mods. A faster pussycat version of the same circuit can be found in the Spectrum, some (if I remember right) older Maggiore or Melco and Icom Repeater Receiver circuits. External op amp sections were added as gain buffers and high speed switches to enhance the internal circuit operation. The Hamtronics transistor hysterisis circuit works ok so don't discount it as a bad design. The receiver is/was a very basic circuit and could be used in modest low power repeater operation without a lot of grief. If you really were interested in more work with the mentioned chips I can and would be happy to email you some circuit diagrams and manuals related to the chips used in quality well engineered designs/circuits (in pdf file format). As in our poor mans repeater project... sometimes when money is tight you try to use whatever you can get you hands on. cheers, skipp __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
RE: [Repeater-Builder] Problem with fan noise in power line.
Doug, The solution is to replace the noisy fan with one that is designed for very low EMI. The first thermostatic switch controlled fan I put on my solar-powered UHF repeater had a whine that modulated the carrier. I then swapped it with a Panasonic fan that was specified for low EMI. Presto! There was no trace of fan noise on the carrier. Part of the problem is the basic design of some RF-noisy fans. Hall-Effect devices are used for commutation, and some designs are inherently noisy. Some of the noise is conducted, and some is radiated, so ferrite rings, series inductors, and capacitors are of little value in filtering the noise. Just choose a low-EMI fan in the first place! 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Doug Hutchison Sent: Tuesday, April 17, 2007 7:09 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Problem with fan noise in power line. Have a system comprising 4m simplex link and 2m repeater running from same PSU. Tried using a brushless fan to boost cooling but when running and connected on the same PSU as the RF kit, the noise generated on 4m TX audio (not 2m), a very loud buzz, is incredible. Obviously the inverter noise is being carried back into the PSU so some sort of filtering is needed as, when the fan is run on a separate supply, there is no problem. Has anyone encountered such a situation and if so what circuit or device was used to cure the noise (other that a second PSU)? Regards, Doug - GM7SVK
RE: [Repeater-Builder] Problem with fan noise in power line.
I too had a fan noise on my GR 300 repeater. As Eric instructed, I replaced the fan with a low EMI. Still had some but a lot less. Then I took the new low EMI fan and removed it from the repeater cabinet and hung it from the big cabinet, holding all the repeater items, so it still blows on the heatsink and it is almost not heard. I had two problems, 1) to high of EMI rated fan, 2) vibration noise. Thank you Eric L. for your help with my problem. Rod KC7VQR Doug, The solution is to replace the noisy fan with one that is designed for very low EMI. The first thermostatic switch controlled fan I put on my solar-powered UHF repeater had a whine that modulated the carrier. I then swapped it with a Panasonic fan that was specified for low EMI. Presto! There was no trace of fan noise on the carrier. Part of the problem is the basic design of some RF-noisy fans. Hall-Effect devices are used for commutation, and some designs are inherently noisy. Some of the noise is conducted, and some is radiated, so ferrite rings, series inductors, and capacitors are of little value in filtering the noise. Just choose a low-EMI fan in the first place! 73, Eric Lemmon WB6FLY
Re: [Repeater-Builder] mc-3357 mc-3359 squelch circui
Ah yes, The JEM squelch. If I look around I can probably find the GIF you sent me that became the comparator section for the SuperSquelch Mk.1. It was pretty good, but there is always room for improvement. By replacing the comparator section with a microcontroller the board can be talored for peoples tastes. I am hoping to write different versions of the firmware to emulate the Micor and MASTR-II with cap mod as well as the continuously variable hang time version. On 4/17/07, Joe Montierth [EMAIL PROTECTED] wrote: A few years ago I designed a dual level squelch circuit that could be a replacement for the Micor type carrier squelch. I built a couple of the prototypes and put them into service, and they worked very well, you really couldn't tell them from the real thing. They were designed around readily available and cheap parts, so replicating it would be very easy. I think total parts costs would be around $5, not counting the board. If anyone is interested, I can supply a PDF of the schematic, or upload it to the site. Somewhere, I have some of the boards, but I don't remember exactly where they went. The schematic I have could probably be simplified even more, it was just an idea that I came up with, and it worked, so I didn't fool around with it anymore. Joe --- skipp025 [EMAIL PROTECTED] wrote: Re: mc-3357 mc-3359 squelch circuit Many receivers used the two mentioned chips... in both commericial, Amateur Radio and classic scanner circuits. I've seen both part numbers converted to tk numbers in Yaesu and Uniden Radios. There are a number of working squelch circuits using the back end section of the chip with and without external op amps. While the Hamtronics circuit is/was rather basic it did work pretty well and was easy to experiment with changes/mods. A faster pussycat version of the same circuit can be found in the Spectrum, some (if I remember right) older Maggiore or Melco and Icom Repeater Receiver circuits. External op amp sections were added as gain buffers and high speed switches to enhance the internal circuit operation. The Hamtronics transistor hysterisis circuit works ok so don't discount it as a bad design. The receiver is/was a very basic circuit and could be used in modest low power repeater operation without a lot of grief. If you really were interested in more work with the mentioned chips I can and would be happy to email you some circuit diagrams and manuals related to the chips used in quality well engineered designs/circuits (in pdf file format). As in our poor mans repeater project... sometimes when money is tight you try to use whatever you can get you hands on. cheers, skipp __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com Yahoo! Groups Links
[Repeater-Builder] Re: Problem with fan noise in power line.
As Rod pointed out, the vibration from the fan causing transmitted noise in his GR300 Rptr. In the Motorola GM,Radius M, and Maxtrac, series mobiles the RX and TX VCO's are very sensitive to vibration. Other radios may be sensitive to vibration also. [EMAIL PROTECTED] wrote: I too had a fan noise on my GR 300 repeater. As Eric instructed, I replaced the fan with a low EMI. Still had some but a lot less. Then I took the new low EMI fan and removed it from the repeater cabinet and hung it from the big cabinet, holding all the repeater items, so it still blows on the heatsink and it is almost not heard. I had two problems, 1) to high of EMI rated fan, 2) vibration noise. Thank you Eric L. for your help with my problem. Rod KC7VQR
