Re: [Repeater-Builder] Re: Astron Power Supply Alert
I don't know if anyone recalls this, but there was a bad run of rectifiers on most of their linear supplies in the late-90's. Astron shipped out replacement rectifiers free of charge. Replacement was easy, one machine screw and nut to secure the rectifier and four space connectors. From what I recall, there MAY have been an AC ripple problem, but most notable was that the power supply got VERY hot from the rectifier shorting out internally. In a worst case, I saw one spew smoke several feet into the air under pressure from around the potting compound. Kurt - Original Message - From: WA Brown brow...@ftc-i.net : What is wrong with the power supply? Here is the contact info for Astron.
Re: [Repeater-Builder] Re: Astron Power Supply Alert
Tom, I'm also a very satisfied Astron user. People whine, but there's nothing like them at their price point. My comment wasn't about the esthetics or hipness of the Yahoo address, but its functionality. They work OK most of the time, but so much illicit stuff is done through disposable e-mail addresses at Yahoo, MSN, Hotmail, etc. that there are times when the inter-ISP blacklist services block them for hours at a time, and the account holder doesn't even know some of his customers are unable to reach his inbox. 73, Paul, AE4KR - Original Message - From: wb6dgn To: Repeater-Builder@yahoogroups.com Sent: Wednesday, October 21, 2009 11:14 PM Subject: [Repeater-Builder] Re: Astron Power Supply Alert Nothing says we're reputable and here to stay like a company e-mail address at yahoo.com! I think I'd find a more reliable way to evaluate a company than the email address they use. Not everyone considers an email address all that important... .
Re: [Repeater-Builder] Re: Astron Power Supply Alert
LOL! Nothing says we're reputable and here to stay like a company e-mail address at yahoo.com! Nothing against the power supplies, miy 1995-vintage RS35 still works fine, but sheesh! 73, Paul AE4KR - Original Message - From: WA Brown To: Repeater-Builder@yahoogroups.com Sent: Tuesday, October 20, 2009 10:00 PM Subject: Re: [Repeater-Builder] Re: Astron Power Supply Alert What is wrong with the power supply? Here is the contact info for Astron. 9 Autry, Irvine, CA 92618 949-458-7277 . FAX:949-458-0826 E-MAIL: astroncorporat...@yahoo.com .
[Repeater-Builder] Re: Astron Power Supply Alert
Nothing says we're reputable and here to stay like a company e-mail address at yahoo.com! I think I'd find a more reliable way to evaluate a company than the email address they use. Not everyone considers an email address all that important. If it gets the job done, WHO CARES who the provider is? I sure don't! My personal experience with Astron has been exemplary in every way, the products, the service, the support. Additionally their longevity has ALREADY proven that they truly ARE here to stay. As a commercial LMR tech. for over 45 years, I've seen more Astron supplies than all other brands put together(except maybe Motorola). THAT says all I need to know. I have NO affiliation with Astron or any other commercial enterprise, and have never had any affiliation with Astron other than a VERY satisfied user. Tom DGN --- In Repeater-Builder@yahoogroups.com, Paul Plack pl...@... wrote: LOL! Nothing says we're reputable and here to stay like a company e-mail address at yahoo.com! Nothing against the power supplies, miy 1995-vintage RS35 still works fine, but sheesh! 73, Paul AE4KR - Original Message - From: WA Brown To: Repeater-Builder@yahoogroups.com Sent: Tuesday, October 20, 2009 10:00 PM Subject: Re: [Repeater-Builder] Re: Astron Power Supply Alert What is wrong with the power supply? Here is the contact info for Astron. 9 Autry, Irvine, CA 92618 949-458-7277 . FAX:949-458-0826 E-MAIL: astroncorporat...@... .
[Repeater-Builder] Re: Astron Power Supply Alert
Hello Eric, Would you kindly provide me with the Tech support email address you used for Astron. Ive been un able to get a good address. Thank you in advance! Gary
Re: [Repeater-Builder] Re: Astron Power Supply Alert
What is wrong with the power supply? Here is the contact info for Astron. 9 Autry, Irvine, CA 92618 949-458-7277 . FAX:949-458-0826 E-MAIL: astroncorporat...@yahoo.com WAB - Original Message - From: Gary ki4...@yahoo.com To: Repeater-Builder@yahoogroups.com Sent: Tuesday, October 20, 2009 11:29 PM Subject: [Repeater-Builder] Re: Astron Power Supply Alert Hello Eric, Would you kindly provide me with the Tech support email address you used for Astron. Ive been un able to get a good address. Thank you in advance! Gary Yahoo! Groups Links
[Repeater-Builder] Re: Astron Power Supply
Joe [EMAIL PROTECTED] wrote: You may have to be careful of the overvoltage protection device if you go too high, I don't remember what it fires at. Depends on the version of the regulator board... sometimes it even fires when you don't want it to. I turned the voltage up on my VS-50M Astron to overcome the voltage drop in the Rigblaster PRWgate PG40 that I use between the power supply and battery. I float the battery at 13.8VDC. I've had no problem for a couple of years so far. The VS-50M is basically the RM-50M with the voltage adjustment on the front panel. 73, Joe, k1ike The only beef with the Astron VS Series Supplies is how they don't like to properly power up into some heavy current loads. Sometimes you need to insert a current limiter in series with the load to get the VS to come up with a heavy load already in place. A high current step-start circuit of sorts... cheers, s. Bernie, My RS35 has a pot for setting the output voltage on the main, only, control board. 73, ron, n9ee/r From: dallasreact112 [EMAIL PROTECTED] mailto:dallasreact112%40yahoo.com Date: 2007/11/13 Tue PM 11:38:46 CST To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com Subject: [Repeater-Builder] Astron Power Supply Has any one had experience with setting output voltage on an Astron RM-50M power supply? I'd like to bump up the voltage to 14.4 V to override a diode junction loss in a battery isolator. Does it have the room to be adjusted up? Thanks Bernie Parker K5BP Ron Wright, N9EE 727-376-6575 MICRO COMPUTER CONCEPTS Owner 146.64 repeater Tampa Bay, FL No tone, all are welcome.
[Repeater-Builder] Re: Astron Power Supply
Email me and I'll reply with a PDF of those pages from the manual. I'm not good at explaining even simple things. My email address is tallinson2 att yahooo dott kom. (All spelled correctly). Tom --- In Repeater-Builder@yahoogroups.com, dallasreact112 [EMAIL PROTECTED] wrote: Has any one had experience with setting output voltage on an Astron RM-50M power supply? I'd like to bump up the voltage to 14.4 V to override a diode junction loss in a battery isolator. Does it have the room to be adjusted up? Thanks Bernie Parker K5BP
[Repeater-Builder] Re: Astron Power Supply Failures
I bought an import made battery load tester off ebay for under $10. The tester even has a meter indication. I added a small fan to move air through it and use it as a high current load where desired. Sometimes I use it as a series resistance. I also use heating elements out of dead hair dryers for nichrome wire resistors. cheers, skipp Bob M. [EMAIL PROTECTED] wrote: I would have gladly run the supply loaded to 28 amps if the resistors could take it. They couldn't. They were heating the room after several minutes, and took half an hour to cool off after that. I did the best I could with the equipment available. I need about 400 watts-worth of load to test these things properly. I step-started the repeater after putting in the working power supply, but it didn't need to be done that way. Astron never responded to my e-mail from Friday, so I'll be rattling their cage Tuesday to see how their warranty procedure works and if it's even worth sending the unit back to them. Bob M.
[Repeater-Builder] Re: Astron Power Supply Failures
Bob, Were you using the standard generic 3AG glass fuse..? Was it a fast or slow blow..? If you still have the dead fuse... who is the mfgr? It takes quite a bit to kill the diodes or a bridge. Replacing the mentioned with a higher capacity type is probably a good idea but you should also toss the generic fuse and get a high spec quality brand proper-value replacement. Something is probably causing the crowbar to fire... the fuse doesn't open fast enough. Are both diodes shorted or just one side? cheers, s. Bob M. [EMAIL PROTECTED] wrote: Some of the regular readers may recall I had an RS35M (bought new in 2002) blow its diodes in July 2006. These were two 35A, 50V bridges made by Diotec. Astron only uses the positive half and wires them in parallel. I replaced these with Vishay GBPC35 rectifiers, tested the supply, and put it aside. A friend loaned me his old RS35M which got the repeater back on the air in 90 minutes. I bought a brand new RS35M supply in July 2006 and finally got around to installing it in October 2006. The other day the same thing happened. The repeater had been quiet all morning, someone called me on it, and mid-way through the CW ID (after transmitting for about 10 seconds), it just went off the air. I grabbed the repaired RS35M, went to the site, and put it into the repeater, pulling the other one back down to my shack. The repeater was back on the air after 3 hours (hey, it was cold outside and I didn't feel like driving up there right away). Back on the bench, I tried a new 8A fuse; it blew immediately. I measured the resistance across the diodes; I read 0 ohms, but without disconnecting them from the transformer, this is not an accurate reading. I'd surmise that one or both bridges have a shorted diode in them. Seems like the same failure as the 2002 supply had. This one, however, is still under warranty. I'm not sure it will be economically feasible to ship it to Astron where they'll put in exactly the same diodes, in the same configuration, where they'll just blow again. Until I hear back from them, I'm not going in there to disconnect the diodes to actually measure them. I've purchased some new 50A 1000V bridges which I will put into these supplies from now on. No more diodes in parallel. Incase you ask, the load on the supply is 25 amps at 14.0 volts, it has plenty of forced air cooling on it, the environment is 70F, and the repeater is low usage: a couple of hours per day with a sustained usage at drive time of about 45 minutes on a busy day. I was taught that running semiconductors (diodes and transistors) in parallel without some kind of load balancing components is a bad thing. I'd rather have a single pair of diodes in these supplies instead of the pairs of bridges. Anyone else care to comment pro or con? Needless-to-say, my next power supply will be a different brand. Bob M. Do you Yahoo!? Everyone is raving about the all-new Yahoo! Mail beta. http://new.mail.yahoo.com
Re: [Repeater-Builder] Re: Astron Power Supply Failures
It was a standard 8A generic 3AG glass fuse. It didn't blow explosively; it just got soft and opened. When I put a new fuse in, it blew instantly with a burst of molten metal coating the insides of the glass. Fuse quality should not be of concern at this point. The fuse shouldn't blow with about 400 watts of load on the supply's output. Also, the crowbar firing shouldn't blow the fuse that quickly, unless almost everything after the diodes has shorted out. If one diode shorts, it'll likely do damage to the other one on the next half cycle. It blew out with the 25A load. The only way to tell for sure is to unwire the two diode bridges and measure them with a meter. But since this is exactly the same failure my first one had, I'm pretty sure it failed in the same way. I'm not pulling the diodes until Astron does something about the under warranty condition. I did disconnect the positive output wire at the capacitor and when I measure across the cap and circuit board, I get a rising resistance of several hundred ohms. When I measure across the red and black leads (disconnected from the cap and regulator board) I get 0.1 ohms in both directions. I would expect to see some resistance from the diodes in at least one direction, but no soap. Someone else mentioned that 25A is the limit for continuous use. Yup, I'm not disagreeing. However it should be capable of that load for hours at a time. Bob M. == --- skipp025 [EMAIL PROTECTED] wrote: Bob, Were you using the standard generic 3AG glass fuse..? Was it a fast or slow blow..? If you still have the dead fuse... who is the mfgr? It takes quite a bit to kill the diodes or a bridge. Replacing the mentioned with a higher capacity type is probably a good idea but you should also toss the generic fuse and get a high spec quality brand proper-value replacement. Something is probably causing the crowbar to fire... the fuse doesn't open fast enough. Are both diodes shorted or just one side? cheers, s. Bob M. [EMAIL PROTECTED] wrote: Some of the regular readers may recall I had an RS35M (bought new in 2002) blow its diodes in July 2006. These were two 35A, 50V bridges made by Diotec. Astron only uses the positive half and wires them in parallel. I replaced these with Vishay GBPC35 rectifiers, tested the supply, and put it aside. A friend loaned me his old RS35M which got the repeater back on the air in 90 minutes. I bought a brand new RS35M supply in July 2006 and finally got around to installing it in October 2006. The other day the same thing happened. The repeater had been quiet all morning, someone called me on it, and mid-way through the CW ID (after transmitting for about 10 seconds), it just went off the air. I grabbed the repaired RS35M, went to the site, and put it into the repeater, pulling the other one back down to my shack. The repeater was back on the air after 3 hours (hey, it was cold outside and I didn't feel like driving up there right away). Back on the bench, I tried a new 8A fuse; it blew immediately. I measured the resistance across the diodes; I read 0 ohms, but without disconnecting them from the transformer, this is not an accurate reading. I'd surmise that one or both bridges have a shorted diode in them. Seems like the same failure as the 2002 supply had. This one, however, is still under warranty. I'm not sure it will be economically feasible to ship it to Astron where they'll put in exactly the same diodes, in the same configuration, where they'll just blow again. Until I hear back from them, I'm not going in there to disconnect the diodes to actually measure them. I've purchased some new 50A 1000V bridges which I will put into these supplies from now on. No more diodes in parallel. Incase you ask, the load on the supply is 25 amps at 14.0 volts, it has plenty of forced air cooling on it, the environment is 70F, and the repeater is low usage: a couple of hours per day with a sustained usage at drive time of about 45 minutes on a busy day. I was taught that running semiconductors (diodes and transistors) in parallel without some kind of load balancing components is a bad thing. I'd rather have a single pair of diodes in these supplies instead of the pairs of bridges. Anyone else care to comment pro or con? Needless-to-say, my next power supply will be a different brand. Bob M. Sucker-punch spam with award-winning protection. Try the free Yahoo! Mail Beta. http://advision.webevents.yahoo.com/mailbeta/features_spam.html
Re: [Repeater-Builder] Re: Astron Power Supply Failures
On 2/12/07, Bob M. [EMAIL PROTECTED] wrote: Someone else mentioned that 25A is the limit for continuous use. Yup, I'm not disagreeing. However it should be capable of that load for hours at a time. We run a mixture of Astron supplies and the stock GE supplies, and almost all of them are running about 50% load... we put the big GE supply on a single repeater and our PA's are never run at full rated output. One of the Astron supplies is the monster 75A (?) model with metering and has been running now continuously (other than a lighting strike many years ago, and power outages and/or maintenance where we choose to turn it off) for close to ten years. That Astron has something blown in the DC Voltmeter, and the Voltmeter is pegged all the time, but it continues to run... and we check voltage with our own DVM's. We've seen no reason to go through the headache of un-racking it to fix the metering circuit, and the ammeter (the one we're usually more interested in anyway -- shows if the usual current draw is happening when we arrive on-site to do work, since we note it in the site notebook) works fine. Beef up. It'll help the stuff last longer. Just like many PA varieties... a 100W PA run at 80W will (generally depending on design) last a very long time. Current in-rush when things first key up and heat both are power supply killers... find supplies that can LOAF at even the worst you can throw at them, and you'll be happier. They'll last seemingly forever. (And now, I'm SURE I've jinxed us... and a PS will blow somewhere, soon. LOL!) Nate WY0X
Re: [Repeater-Builder] Re: Astron Power Supply Failures
At 12:53 PM 2/12/2007, you wrote: Someone else mentioned that 25A is the limit for continuous use. Yup, I'm not disagreeing. However it should be capable of that load for hours at a time. ---Well, under the best of conditions, probably. But think about it - you're pushing something pretty much against its ceiling which leaves no room for error. Don't forget about the little niceties that exist at many repeater sites, not the least of which is poor transient protection and voltage primary voltage regulation. That doesn't leave any overhead (or at least very little). A good analogy would be flying a Cessna at its rated ceiling and then expecting it to provide greater altitude, even a little. Massive overkill is always a good thing! Ken -- President and CTO - Arcom Communications Makers of the world famous RC210 Repeater Controller and accessories. http://www.arcomcontrollers.com/ Authorized Dealers for Kenwood and Telewave and we offer complete repeater packages! AH6LE/R - IRLP Node 3000 http://www.irlp.net
[Repeater-Builder] Re: Astron Power Supply Failures
Bob M. [EMAIL PROTECTED] wrote: Someone else mentioned that 25A is the limit for continuous use. Yup, I'm not disagreeing. However it should be capable of that load for hours at a time. The heatsink temp will tell you the real story. Astron Linear Power Supply heatsinks are not well sized. s.
Re: [Repeater-Builder] Re: Astron Power Supply Failures
Well, I know that the transformer makes heat all by itself, but in the repeater cabinet, a fan is blowing directly on the back of the supply and I've never had anything get hot inside in over 5 years of operation (except for the MaxTrac exciter running at 6 watts, but the fan keeps it cool too). I also load-tested the supply that's currently running, with a pair of 1 ohm resistors in parallel. They got really hot after several minutes while the supply itself stayed ice cold. I did discover that the supplies don't like being powered up with a 1/2 ohm load across the output. I only got 5V/10A; I presume that was a foldback of some kind. When I disconnected the load, everything went right back to 14V. With the supply running, the only thing that changed when I reconnected the load was the ammeter went from 0 to 28. The voltage at the output terminals only dropped a few dozen millivolts. Bob M. == --- skipp025 [EMAIL PROTECTED] wrote: Bob M. [EMAIL PROTECTED] wrote: Someone else mentioned that 25A is the limit for continuous use. Yup, I'm not disagreeing. However it should be capable of that load for hours at a time. The heatsink temp will tell you the real story. Astron Linear Power Supply heatsinks are not well sized. s. Get your own web address. Have a HUGE year through Yahoo! Small Business. http://smallbusiness.yahoo.com/domains/?p=BESTDEAL
[Repeater-Builder] Re: Astron Power Supply Failures
Bob M. [EMAIL PROTECTED] wrote: Well, I know that the transformer makes heat all by itself, but in the repeater cabinet, a fan is blowing directly on the back of the supply and I've never had anything get hot inside in over 5 years of operation (except for the MaxTrac exciter running at 6 watts, but the fan keeps it cool too). Even with the fan... if you're pulling 25 amps from the supply the heat sinks will get warm real warm. The fan at best can only keep it from getting real hot. So hot you couldn't keep your hand on the heat sink metal. I also load-tested the supply that's currently running, with a pair of 1 ohm resistors in parallel. They got really hot after several minutes while the supply itself stayed ice cold. How about 45 minutes in operation at 25 amps load? Several minutes doesn't really cut the mustard. I did discover that the supplies don't like being powered up with a 1/2 ohm load across the output. I only got 5V/10A; I presume that was a foldback of some kind. When I disconnected the load, everything went right back to 14V. With the supply running, the only thing that changed when I reconnected the load was the ammeter went from 0 to 28. The voltage at the output terminals only dropped a few dozen millivolts. Bob M. The astron supply regulator design does not power up well into high current demand. The variable vls supply is even more sluggish. There are 2 step start methods used by some people to deal with this design quirk. s.
Re: [Repeater-Builder] Re: Astron Power Supply Failures
I would have gladly run the supply loaded to 28 amps if the resistors could take it. They couldn't. They were heating the room after several minutes, and took half an hour to cool off after that. I did the best I could with the equipment available. I need about 400 watts-worth of load to test these things properly. I step-started the repeater after putting in the working power supply, but it didn't need to be done that way. Astron never responded to my e-mail from Friday, so I'll be rattling their cage Tuesday to see how their warranty procedure works and if it's even worth sending the unit back to them. Bob M. == --- skipp025 [EMAIL PROTECTED] wrote: Bob M. [EMAIL PROTECTED] wrote: Well, I know that the transformer makes heat all by itself, but in the repeater cabinet, a fan is blowing directly on the back of the supply and I've never had anything get hot inside in over 5 years of operation (except for the MaxTrac exciter running at 6 watts, but the fan keeps it cool too). Even with the fan... if you're pulling 25 amps from the supply the heat sinks will get warm real warm. The fan at best can only keep it from getting real hot. So hot you couldn't keep your hand on the heat sink metal. I also load-tested the supply that's currently running, with a pair of 1 ohm resistors in parallel. They got really hot after several minutes while the supply itself stayed ice cold. How about 45 minutes in operation at 25 amps load? Several minutes doesn't really cut the mustard. I did discover that the supplies don't like being powered up with a 1/2 ohm load across the output. I only got 5V/10A; I presume that was a foldback of some kind. When I disconnected the load, everything went right back to 14V. With the supply running, the only thing that changed when I reconnected the load was the ammeter went from 0 to 28. The voltage at the output terminals only dropped a few dozen millivolts. Bob M. The astron supply regulator design does not power up well into high current demand. The variable vls supply is even more sluggish. There are 2 step start methods used by some people to deal with this design quirk. s. Sucker-punch spam with award-winning protection. Try the free Yahoo! Mail Beta. http://advision.webevents.yahoo.com/mailbeta/features_spam.html
[Repeater-Builder] Re: Astron Power Supply Failures
--- In Repeater-Builder@yahoogroups.com, skipp025 [EMAIL PROTECTED] wrote: Bob, Were you using the standard generic 3AG glass fuse..? Was it a fast or slow blow..? If you still have the dead fuse... who is the mfgr? It takes quite a bit to kill the diodes or a bridge. Replacing the mentioned with a higher capacity type is probably a good idea but you should also toss the generic fuse and get a high spec quality brand proper-value replacement. Something is probably causing the crowbar to fire... the fuse doesn't open fast enough. Are both diodes shorted or just one side? cheers, s. Bob M. msf5kguru@ wrote: Some of the regular readers may recall I had an RS35M (bought new in 2002) blow its diodes in July 2006. These were two 35A, 50V bridges made by Diotec. Astron only uses the positive half and wires them in parallel. I replaced these with Vishay GBPC35 rectifiers, tested the supply, and put it aside. A friend loaned me his old RS35M which got the repeater back on the air in 90 minutes. I bought a brand new RS35M supply in July 2006 and finally got around to installing it in October 2006. The other day the same thing happened. The repeater had been quiet all morning, someone called me on it, and mid-way through the CW ID (after transmitting for about 10 seconds), it just went off the air. I grabbed the repaired RS35M, went to the site, and put it into the repeater, pulling the other one back down to my shack. The repeater was back on the air after 3 hours (hey, it was cold outside and I didn't feel like driving up there right away). Back on the bench, I tried a new 8A fuse; it blew immediately. I measured the resistance across the diodes; I read 0 ohms, but without disconnecting them from the transformer, this is not an accurate reading. I'd surmise that one or both bridges have a shorted diode in them. Seems like the same failure as the 2002 supply had. This one, however, is still under warranty. I'm not sure it will be economically feasible to ship it to Astron where they'll put in exactly the same diodes, in the same configuration, where they'll just blow again. Until I hear back from them, I'm not going in there to disconnect the diodes to actually measure them. I've purchased some new 50A 1000V bridges which I will put into these supplies from now on. No more diodes in parallel. Incase you ask, the load on the supply is 25 amps at 14.0 volts, it has plenty of forced air cooling on it, the environment is 70F, and the repeater is low usage: a couple of hours per day with a sustained usage at drive time of about 45 minutes on a busy day. I was taught that running semiconductors (diodes and transistors) in parallel without some kind of load balancing components is a bad thing. I'd rather have a single pair of diodes in these supplies instead of the pairs of bridges. Anyone else care to comment pro or con? Needless-to-say, my next power supply will be a different brand. Bob M. _ Do you Yahoo!? Everyone is raving about the all-new Yahoo! Mail beta. http://new.mail.yahoo.com Hi, your friend was quite correct in what he said about doides/transistors in paralell without current sharing resistors (say 0.1R) is VERY bad practice.Without you get current hogging) where one device takes the lions share of the current is overloaded goes short and takes down the other device.Many power supplies sold kere in the U.K suffer this design fault.A supply may be quoted as 20a continuous and 25a surge with the bridge rectifier quoted by the manufacturer quoting 25a peak current!.Needless to say over the years I have repaired quite a few!.The other failure is the smoothing capacitors take quite a hammering too.Good practice also says 2200uF per amp of output current,rarely fitted,or of adequate ripple-current so they heat up and commonly explode.Power supply design is NOT a Black Art if the basic rules are followed and the supply is built a standard and not seen as a cost-cutting exercise then reliability is then not an issue. G8UMX(30 years in military and defence electronics)
[Repeater-Builder] Re: Astron power supply question
If you go back far enough.. the mfgr was Holiday Rambler. skipp Tedd Doda [EMAIL PROTECTED] wrote: I'm trying to remember the brand John, but I've repaired many of these switchers a year or so ago. The company is out of business, therefore the repair (for an RV company). There are two low value resistors (10 ohm?) that feed the gates of the MOSFETs, which open. Simply change these with higher wattage units and they live happily. Originally 1/4 watt and I swapped them with 1/2 watt. Pain to take apart but worth it. Tedd Doda, VE3TJD Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Astron Power Supply Crowbars
I have read with interest the recent postings on the Astron Power Supplies and Crowbars. Question - has this problem been primarily with the switching power supplies or the transformer based power supplies? We have a Astron RS-20A and a RS-35A that we have been running for a couple of years without problems in a high RF environment. Have the switching power supplies such as the SS-25 and SS-30 from Astron had any known problems? Thanks Steve Hansen --- In Repeater-Builder@yahoogroups.com, skipp025 [EMAIL PROTECTED] wrote: Most of the crowbar problems I've sourced once past the Astron regulator board were traced to weak filter caps of aged units. The crowbar circuit works well. skipp Daron J. Wilson [EMAIL PROTECTED] wrote: Let's not lose sight of the fact that the motor circuits that are generating the spikes should be examined for ways to reduce or eliminate same. Moreover, tinkering with the power supply crowbar circuits is really treating the symptom rather than the problem. I have to disagree. Both of my rack mount 50 amp supplies have done this, on remote sites or in the garage with NO problem on the input side. If you try to draw more than 10-12 amps when you turn them on, it immediately crowbars. The only way to get it to run is to turn it off, drain the caps, remove the load and turn it back on. Then you can attach the load *spark* and it works fine. That is the design flaw that I feel needs to be corrected. 73 N7HQR Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Astron Power Supply Crowbars
Most of the crowbar problems I've sourced once past the Astron regulator board were traced to weak filter caps of aged units. The crowbar circuit works well. skipp Daron J. Wilson [EMAIL PROTECTED] wrote: Let's not lose sight of the fact that the motor circuits that are generating the spikes should be examined for ways to reduce or eliminate same. Moreover, tinkering with the power supply crowbar circuits is really treating the symptom rather than the problem. I have to disagree. Both of my rack mount 50 amp supplies have done this, on remote sites or in the garage with NO problem on the input side. If you try to draw more than 10-12 amps when you turn them on, it immediately crowbars. The only way to get it to run is to turn it off, drain the caps, remove the load and turn it back on. Then you can attach the load *spark* and it works fine. That is the design flaw that I feel needs to be corrected. 73 N7HQR Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: Astron Power Supply Crobars
Is that board rebuildable ?? MH - Original Message - From: Joe D [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Wednesday, September 01, 2004 8:39 AM Subject: [Repeater-Builder] Re: Astron Power Supply Crobars Allow me to elaborate. I have an RM-35M. It has been in continuous repeater service for more than 10 years without a hiccup. Recently our hosts did some electrical work in the building. They installed new elevator motors and emergency power. We are now connected to the emergency power through a very large (~60lbs) ferro- resonate transformer. The elevator motors and controllers are not in the same room as the repeater, but the main power passes through our room. The repeater has been in the same location without any problems from the elevators for 30-years. After the change the RM-35M started crowbaring once or twice per day. I replaced the power supply with another RM-35M. It has been running fine for a couple of weeks now. The original power supply, plugged in on my workbench, with no load, will crowbar after running for 3 to 12 hours. So, will someone tell me about this replacement regulator board of Skipp's? JoeD, N2UF --- In Repeater-Builder@yahoogroups.com, Joe [EMAIL PROTECTED] wrote: I have an RM-35 that has run for years without the crowbar ever operating. Check the output voltage, check it for AC ripple. 73, Joe, k1ike --- Joe D [EMAIL PROTECTED] wrote: I have an Astron RM-35M that runs for a few hours and then crowbars. Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Astron Power Supply Crobars
Rebuilding the original RS-35 regulator board doesn't fix the design problems. I have a box full of old astron regulator boards that I should sell on Ebay, but I'm afraid someone will place them in service and damage their equipment. skipp [EMAIL PROTECTED] www.radiowrench.com/sonic Mark Holman [EMAIL PROTECTED] wrote: Is that board rebuildable ?? MH - Original Message - From: Joe D [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Wednesday, September 01, 2004 8:39 AM Subject: [Repeater-Builder] Re: Astron Power Supply Crobars Allow me to elaborate. I have an RM-35M. It has been in continuous repeater service for more than 10 years without a hiccup. Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Astron Power Supply Crowbars
I have never had an RS (linear) Astron power supply go into crowbar mode, but I can see why a healthy spike could cause that to happen. I have RS-7, RS-12, RS-20, and RS-35 units that have been working fine for many years, although all of my new units are SS (switching) supplies. The RS-35M has a typical crowbar circuit, which comprises an SCR across the output, and a simple trigger circuit. The gate of the SCR has a 0.1 uF capacitor, C102, to bypass spikes and prevent (?) false operation. My gut feeling is that this capacitor should be much larger to do its job reliably; I would replace it with a 2.2 uF tantalum capacitor in parallel with a 510 pF silver-mica capacitor. Let's not lose sight of the fact that the motor circuits that are generating the spikes should be examined for ways to reduce or eliminate same. Moreover, tinkering with the power supply crowbar circuits is really treating the symptom rather than the problem. 73, Eric Lemmon WB6FLY Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: Astron Power Supply Crobars
I work for a wireless company, sometimes rooftop sites near elevators and other motor operated devices can cause tremendous voltage spikes on the power line. Your easiest fix would be to put a UPS that does line conditioning on the Astron power supply. This should smooth out any AC glitches that come down the line. Joe At 08:39 AM 9/1/2004, you wrote: Allow me to elaborate. I have an RM-35M. It has been in continuous repeater service for more than 10 years without a hiccup. Recently our hosts did some electrical work in the building. They installed new elevator motors and emergency power. We are now connected to the emergency power through a very large (~60lbs) ferro- resonate transformer. The elevator motors and controllers are not in the same room as the repeater, but the main power passes through our room. The repeater has been in the same location without any problems from the elevators for 30-years. After the change the RM-35M started crowbaring once or twice per day. I replaced the power supply with another RM-35M. It has been running fine for a couple of weeks now. The original power supply, plugged in on my workbench, with no load, will crowbar after running for 3 to 12 hours. So, will someone tell me about this replacement regulator board of Skipp's? JoeD, N2UF --- In Repeater-Builder@yahoogroups.com, Joe [EMAIL PROTECTED] wrote: I have an RM-35 that has run for years without the crowbar ever operating. Check the output voltage, check it for AC ripple. 73, Joe, k1ike --- Joe D [EMAIL PROTECTED] wrote: I have an Astron RM-35M that runs for a few hours and then crowbars. Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/ All outgoing email scanned with Norton AntiVirus2004. Yahoo! Groups Links To visit your group on the web, go to:http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
[Repeater-Builder] Re: Astron Power Supply Crobars
Allow me to elaborate. I have an RM-35M. It has been in continuous repeater service for more than 10 years without a hiccup. Recently our hosts did some electrical work in the building. They installed new elevator motors and emergency power. We are now connected to the emergency power through a very large (~60lbs) ferro- resonate transformer. The elevator motors and controllers are not in the same room as the repeater, but the main power passes through our room. The repeater has been in the same location without any problems from the elevators for 30-years. After the change the RM-35M started crowbaring once or twice per day. I replaced the power supply with another RM-35M. It has been running fine for a couple of weeks now. The original power supply, plugged in on my workbench, with no load, will crowbar after running for 3 to 12 hours. So, will someone tell me about this replacement regulator board of Skipp's? JoeD, N2UF --- In Repeater-Builder@yahoogroups.com, Joe [EMAIL PROTECTED] wrote: I have an RM-35 that has run for years without the crowbar ever operating. Check the output voltage, check it for AC ripple. 73, Joe, k1ike --- Joe D [EMAIL PROTECTED] wrote: I have an Astron RM-35M that runs for a few hours and then crowbars. Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Astron Power Supply
Hello there, The LM-723 regulator is often placed in under engineered circuits. There are on-board internal amplifier loops, which are susceptible to RFI and high frequency glitches - noise. Proper LM-723 pre-regulation is another common circuit shortfall. The end result is often seen as erratic operation, crowbar circuit firing and regulator failure. Crowbar firing is more common in aged units with older filter capacitors under relatively heavy loads. Many Astron power supplies work well for decades, a lot of the problematic supply's surface in operational circuits with higher impedance and reactive loads. The load impedance and current demand presented to the supply can be a big factor in its reliability. I have an actual exact drop in replacement Astron Regulator Board, which has improved LM-723 pre-regulation, additional RFI and noise bypassing and some minor value changes. I test each regulator for proper operation, I've never had one fail, nor the crowbar circuit fire, even at high-level RF sites. It's not Astron's faultÂ… they are certainly not the first, nor the last person to miss-understand or overlook the LM-723 regulator layout. I've found very few LM-723 regulator circuit designs done really well. The 723 Regulator is an excellent building block, but making one play well with a nearby 50kw broadcast transmitter can be a test of ones engineering skills. Fortunately, the data sheet has all the required information. Much of the mentioned data sheet information is often overlooked. My exact size/named/replacement drop in regulator board is $34.95 plus $4.35 SH. You simply unscrew and unsolder your original regulator board after noting (and writing down) the original wire connection points. The replacement board drops right in and you solder the corresponding original wires to the same locations. The board connection points appear almost exact (but the circuit is not). If your power supply was working before the retrofit, you simply power up, test and go. Each regulator board is tested before they are sent out. If your power supply had previously failed, you should first test the pass driver transistors, emitter ballast resistors and a few other small items before you re-apply power the supply. Although I hadn't originally made these boards available for resale, I will provide an instruction sheet with some additional test repair information. With some revision, the updated regulator circuit is similar in appearance to the original Astron Design with circuit and part value updates in place. Hope that helps Cheers, Skipp Skipp025 at yahoo.com www.radiowrench.com www.radiowrench.com/sonic : Hi Skipp, : Could you please post the info about your : upgraded circuit board for the Astron RS-35 : to the list? Many of us would like to know : more about it. : Thanks much. : Doug VA7DD Joe D [EMAIL PROTECTED] wrote: I have an Astron RM-35M that runs for a few hours and then crowbars. Someone tell me more about this upgraded circuit by Skipp. JoeD [EMAIL PROTECTED] Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
