Re: [Repeater-Builder] Micor Stock Power Supplies
At 2/27/2010 09:56 AM, you wrote: I have been following the 9.6 Volt Micor Voltage information. One post indicated that if one were to replace the Stock MICOR Supply with a switcher and add the 9.6 Volt circuit, the monthly electric bill to run the repeater could be significantly reduced. Is this due to the fact that the switcher, in the standby mode, draws much less current and therefore cost less to operate or is it this combined with efficiently when the repeater is in operation. I have stock MICOR and MASTR II Supplies and would like your expertise on the merits of replacing them with one large switcher or a couple switchers. As always thanks in advance for your input and sharing your experiences with us. A local multi-band repeater system is having IMD problems, requested a CTCSS change to resolve one of them. After describing the sound of the low-level (~-70 dBc) spurs I'm seeing a few hundred kHz either side of the 440 output of the system, the owner told me that the IMD hitting his other inputs sounded the same. I asked if he was using a switching supply to power the system he said yes. I recommended that he replace it with a linear supply; I suspect that will solve all of his IMD problems. Will let you know... Bob NO6B
RE: [Repeater-Builder] Micor Stock Power Supplies
Bob, Let's not denigrate switching power supplies as a class, just because of a few bad apples. Switchers-as a class- are more efficient and reliable than linear supplies. Sure, there may a few brands out there that are spur generators, but not the top-of-the-line switchers from DuraComm, Samlex, Astron, Astec, AEG, and others. QST Magazine has reported on a number of switching power supplies and found that the better brands produced no detectable interference in the HF bands- which are far more vulnerable to spurs than are VHF or UHF repeaters. See the product reviews in QST issues of January 2000, September 2000, July 2006, and August 2009. I rest my case. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of n...@no6b.com Sent: Sunday, February 28, 2010 8:31 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Micor Stock Power Supplies At 2/27/2010 09:56 AM, you wrote: I have been following the 9.6 Volt Micor Voltage information. One post indicated that if one were to replace the Stock MICOR Supply with a switcher and add the 9.6 Volt circuit, the monthly electric bill to run the repeater could be significantly reduced. Is this due to the fact that the switcher, in the standby mode, draws much less current and therefore cost less to operate or is it this combined with efficiently when the repeater is in operation. I have stock MICOR and MASTR II Supplies and would like your expertise on the merits of replacing them with one large switcher or a couple switchers. As always thanks in advance for your input and sharing your experiences with us. A local multi-band repeater system is having IMD problems, requested a CTCSS change to resolve one of them. After describing the sound of the low-level (~-70 dBc) spurs I'm seeing a few hundred kHz either side of the 440 output of the system, the owner told me that the IMD hitting his other inputs sounded the same. I asked if he was using a switching supply to power the system he said yes. I recommended that he replace it with a linear supply; I suspect that will solve all of his IMD problems. Will let you know... Bob NO6B
Re: [Repeater-Builder] Micor Stock Power Supplies
You wrote: Switchers -as a class- are more efficient and reliable than linear supplies. As a Class... More efficient - yes, More reliable - that's debatable. In the two-way radio world, linear supplies are the rule, switchers are the exception. In 25 or 30 years, we'll see if switchers are 'really' as reliable. In my experience with switchers (as a class), they are hard on filter capacitors, with failures of them way before the normal 'dry out' time - many times in just a few years. There are a few tower management companies that I know of that won't let you install a switcher because of the possibility of interference. The same companies also do not let anyone install LMR coax onto the site. I'll be interested to see the results too, Bob. Kevin
RE: [Repeater-Builder] Micor Stock Power Supplies
Kevin, So, these tower management companies no longer allow the latest Motorola and Kenwood stations- which come with switching power supplies- to be installed at their sites? 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Kevin Custer Sent: Sunday, February 28, 2010 3:36 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Micor Stock Power Supplies snip There are a few tower management companies that I know of that won't let you install a switcher because of the possibility of interference. The same companies also do not let anyone install LMR coax onto the site. I'll be interested to see the results too, Bob. Kevin
Re: [Repeater-Builder] Micor Stock Power Supplies
What's the rationale behind the LMR ban? Leakage? lh On Sun, Feb 28, 2010 at 6:35 PM, Kevin Custer kug...@kuggie.com wrote: You wrote: Switchers -as a class- are more efficient and reliable than linear supplies. As a Class... More efficient - yes, More reliable - that's debatable. In the two-way radio world, linear supplies are the rule, switchers are the exception. In 25 or 30 years, we'll see if switchers are 'really' as reliable. In my experience with switchers (as a class), they are hard on filter capacitors, with failures of them way before the normal 'dry out' time - many times in just a few years. There are a few tower management companies that I know of that won't let you install a switcher because of the possibility of interference. The same companies also do not let anyone install LMR coax onto the site. I'll be interested to see the results too, Bob. Kevin
Re: [Repeater-Builder] Micor Stock Power Supplies
--- On Sun, 2/28/10, Larry Horlick llhorl...@gmail.com wrote: From: Larry Horlick llhorl...@gmail.com Subject: Re: [Repeater-Builder] Micor Stock Power Supplies To: Repeater-Builder@yahoogroups.com Date: Sunday, February 28, 2010, 7:26 PM What's the rationale behind the LMR ban? Leakage? The LMR type coax is fine for a while. Then the braid and foil start rubbing against each other and you get noise in the receiver and maybe other close in receivers.
Re: [Repeater-Builder] Micor Stock Power Supplies
I've never heard of it. As an installer, I'm always under pressure to use less expensive feedlines than the venerable Heliax, and I had often considered LMR, but never actually succumbed to the temptation. This is interesting information. Is this a well documented phenomenon? Anyone else like to chime in on this... Larry On Sun, Feb 28, 2010 at 8:11 PM, Ralph Mowery ku...@yahoo.com wrote: --- On *Sun, 2/28/10, Larry Horlick llhorl...@gmail.com* wrote: From: Larry Horlick llhorl...@gmail.com Subject: Re: [Repeater-Builder] Micor Stock Power Supplies To: Repeater-Builder@yahoogroups.com Date: Sunday, February 28, 2010, 7:26 PM What's the rationale behind the LMR ban? Leakage? The LMR type coax is fine for a while. Then the braid and foil start rubbing against each other and you get noise in the receiver and maybe other close in receivers.
Re: [Repeater-Builder] Micor Stock Power Supplies
Andrew has a coaxial cable similar (remarkably similar) to LMR, called CNT. I guess the same cautions apply to this product, too? lh On Sun, Feb 28, 2010 at 9:22 PM, Mike Morris WA6ILQ wa6...@gmail.comwrote: Go here: http://www.repeater-builder.com/antenna/ant-sys-index.html Scroll down to the article titled Recommended Coax and Connectors for the iDEN Enhanced Base Transceiver System. and read it, and the one following it (HELIAX Coaxial Cable for Low Intermodulation Generation. Basically the Time Wire LMR series of cables (that's a LMR followed by any 3 or 4 digit number) are not long-term duplexable feedlines. They have an internal construction that has aluminum foil rubbing against copper braid and the dissimilar metals create desense. Also the center conductor is copper clad aluminum. One of the kickers is that in many cases the noise problem doesn't happen immediately - the cable works fine for a while, then gets noisy, and the cable doesn't get immediate attention - because it's working fine. Mike WA6ILQ At 04:26 PM 02/28/10, you wrote: What's the rationale behind the LMR ban? Leakage? lh On Sun, Feb 28, 2010 at 6:35 PM, Kevin Custer kug...@kuggie.com wrote: You wrote: Switchers -as a class- are more efficient and reliable than linear supplies. As a Class... More efficient - yes, More reliable - that's debatable. In the two-way radio world, linear supplies are the rule, switchers are the exception. In 25 or 30 years, we'll see if switchers are 'really' as reliable. In my experience with switchers (as a class), they are hard on filter capacitors, with failures of them way before the normal 'dry out' time - many times in just a few years. There are a few tower management companies that I know of that won't let you install a switcher because of the possibility of interference. The same companies also do not let anyone install LMR coax onto the site. I'll be interested to see the results too, Bob. Kevin
Re: [Repeater-Builder] Micor Stock Power Supplies
Sorry, I cannot answer that question. My reference was more toward the replacement of an existing linear supply or new installations such as GMRS or Amateur Radio systems - repeater or otherwise. Whether or not their rule applies to newer Motorola or other commercial radio manufacturers - I'm not certain. I am told that Motorola offers alternative powering methods to systems that normally come with switching supplies. I'm not totally sure why... possibly there are companies that aren't totally sold on switcher technology? Unfortunately, like with so many things, price dictates quality. If you buy a JAN crystal, be prepared to have it drift all over the place. If you buy a cheap switcher, be prepared to have it throw garbage out all over the place. While the better switchers like Samlex and DuraComm are good performers, many of us will buy something cheap. With education, more of us will buy the better product, like International Crystals with temperature compensation performed by them. Kevin So, these tower management companies no longer allow the latest Motorola and Kenwood stations- which come with switching power supplies- to be installed at their sites? 73, Eric Lemmon WB6FLY snip There are a few tower management companies that I know of that won't let you install a switcher because of the possibility of interference. The same companies also do not let anyone install LMR coax onto the site. I'll be interested to see the results too, Bob.
Re: [Repeater-Builder] Micor Stock Power Supplies
--- On Sun, 2/28/10, Larry Horlick llhorl...@gmail.com wrote: From: Larry Horlick llhorl...@gmail.com Subject: Re: [Repeater-Builder] Micor Stock Power Supplies To: Repeater-Builder@yahoogroups.com Date: Sunday, February 28, 2010, 9:49 PM Andrew has a coaxial cable similar (remarkably similar) to LMR, called CNT. I guess the same cautions apply to this product, too? lh There are several makes of similar cable. They all hae a foil shield and then a braid. I think it was Belden 9913 and a few other numbers that came out first. I use Davis BuryFlex for my ham station. It is very good cable, but just not for duplex operations. I have seen a few repeaters using similar cable and they have worked fine for several years. I have also seen a couple of repeaters that worked fine for a short time and then noise started. Replace the cable with hardline and the noise stopped. The cable would still be fine for use at home with a transceiver, just not for duplex service.
Re: [Repeater-Builder] Micor Stock Power Supplies
At 09:56 AM 02/27/10, you wrote: I have been following the 9.6 Volt Micor Voltage information. One post indicated that if one were to replace the Stock MICOR Supply with a switcher and add the 9.6 Volt circuit, the monthly electric bill to run the repeater could be significantly reduced. Is this due to the fact that the switcher, in the standby mode, draws much less current and therefore cost less to operate or is it this combined with efficiently when the repeater is in operation. I have stock MICOR and MASTR II Supplies and would like your expertise on the merits of replacing them with one large switcher or a couple switchers. As always thanks in advance for your input and sharing your experiences with us. 73 JIM KA2AJH Wellsville, N.Y. I'm only mentioning this as food for thought. Over 10 years ago I was shown a Micor station that had been modified to reduce the electric bill. I do not know if it was GMRS, UHF amateur or 2m amateur, and I never heard if it was a short term test or a long term installation. I do not know how much the power bill was reduced, but it was probably significant. We were up at a site that had individual AC power metering for each customer. There was a row of power meters on one wall, and each customer had a 120v 30a twist lock outlet in a box mounted on the ceiling. A heavy cord dropped down to each rack. We were there to swap out a transmitter and verify the duplexer tuning. After we were done the gentleman I was with showed me an interesting system that was in an open frame rack on the other side of the room... it belonged to someone else, but was in the same building. A diagram was taped to a rack panel in the rack and the information below is from my memory of that diagram. The owner had isolated the main channel receiver, the control receiver, and the repeater controller (an Scom 5k) from the stock Micor supply and powered them from a 12v 7.5ah gell cell charged by a separate switching supply that had been carefully adjusted to the proper float voltage. The notes on the diagram stressed that the voltage had to be adjusted to better than 1/10 of a volt or it would shorten the battery life. The stock supply remained connected to the transmitter, and the AC to it was switched on and off with the PTT line run through a time delay relay so the AC would stay on for 10 minutes after the input signal went away. In your case you could do something similar. The gell-cell would be optional - the site had reliable power, I don't know why the system had the gell cell. Mike WA6ILQ
RE: [Repeater-Builder] Micor Stock Power Supplies
Jim, I performed load tests on many different power supplies, including the ferroresonant supplies common to Motorola and GE stations. The results are posted in the Power Supplies folder in the Files section of the Repeater-Builder Group. As shown by the efficiency numbers, switchers are far more economical to operate than linear or ferroresonant supplies- especially at the low current draw in standby mode. Indeed, some busy mountaintop repeater sites are heated solely by the waste heat produced by vintage power supplies. If you're paying for power at your repeater site, your clunker power supply is costing you a chunk of change. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of James Sent: Saturday, February 27, 2010 9:56 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Micor Stock Power Supplies I have been following the 9.6 Volt Micor Voltage information. One post indicated that if one were to replace the Stock MICOR Supply with a switcher and add the 9.6 Volt circuit, the monthly electric bill to run the repeater could be significantly reduced. Is this due to the fact that the switcher, in the standby mode, draws much less current and therefore cost less to operate or is it this combined with efficiently when the repeater is in operation. I have stock MICOR and MASTR II Supplies and would like your expertise on the merits of replacing them with one large switcher or a couple switchers. As always thanks in advance for your input and sharing your experiences with us. 73 JIM KA2AJH Wellsville, N.Y.
