Astron supplies are the easiest power supplies to repair, I buy them whenever they seem affordable. Repairing them cost pennies and even the transformer is not that expensive. I have replaced several of them with torroidial surplus transformers in the past. one thing I noticed is that some models have a extreme fast loop speed so if you run SSB peaks one would trigger either over voltage or over current. Slowing down the feedback loop(s) with a small 0.1 -1uf capacitor prevents this from happening.
Ape, I use a variable carbon pile load (Harbor Freight) to test the full output of these large supplies. Often times there is a problem with the Astron's where there is a current sense resistor of the incorrect value. That makes the supply "fold back" when the load is less than the rated amps of the supply. The Astron schematic is available online and all the supplies are basically the same. Keep a few of the voltage regulator chips on hand (I tape one inside the supply) for easy replacement when they go bad. 73 Bro.
I wish you good luck with your Astron PS. I never had good luck with them and will never buy another. As noted by the previous comments they're easy to work on (whats not said is 'that's because they need to be'). In my last job as an Electronics Repairman for towboats on the inland waterways (mostly marine FM VHF and HF SSB radios) I had to repair tons of them. I always attributed that to the generators on the boats... But found out after I bought a 35M for my shack that's not always the case. A couple of months in the LM723 regulator went out while I was gone and not operating, so I replaced it (socketed) and didn't bother with warranty. Right after the warranty expired the transformer shorted turning the fuse (and several after while troubleshooting) into flashbulbs, again on but not being loaded (no thunderstorms were around or other electrical damage in my home, its MOV was good). When the MOV is disabled and all the output leads are loose and isolated there's no doubt what it is. I now consider Astron's a Hobby PS. For me at least, they are a hobby in their own right to keep running. I'm retired now and look for reliability over a continuing project. The PS I'd built before the 35M was a Tank that never gave problems (gave it to a new ham). I have heard other 723 based PS's can have problems also, so I just got a Yaesu FP-1030A ($230 new) for its good reputation and lack of 723. Time will tell. I refuse to use switching PS's for my rigs. YMMV! (BTW the few Icom Xfmr PS's I saw on the boats were very reliable) 73's mike - N4ONL (The 35M will be parted our or a basis for another Tank some day, sans regulator board)
As I Said YMMV! Several folks seem to have no problems with them. Also after Astron added the RF bypass cap to the output, the crowbar wouldn't trigger as easily from RF. I can't remember what output transistors they use, I think it used to be 2N3055's but I could be wrong, I always replaced bad output(s) with sets of 4 x 2N3772's which have a higher rating. You may get decades of trouble free use out of yours, I hope you do! 73's mike - N4ONL
It looks like the current limit kicked in causing those voltage swings. Try running the test again with the current knob fully clockwise and give er the beans. I bet you'll be good.
I'd think that at 1/2 way it should do more than 3A, but in either case I'd expect that the voltage may dip but not swing like that. Thanks for the comment Nate 👍
@@TheSmokinApe I agree with you that I'd expect it to do more than 3A half way. I wonder if it's not a linear adjustment. I've used linear power supplies in school which would "flicker" between full output voltage and zero when they hit the current limit. I wouldn't have believed it had I not seen it myself. Let's test it out, son! Looking forward to the next video.
@@TheSmokinApe Hi Ape. I believe the supply was acting exactly how it should. The current knob is an overcurrent limit setting. So when the load hit that limit, the supply just shutoff. I suspect that when the load tester saw the voltage go away, it shutoff the load. It probably has a minimum voltage limit so it doesn't damage batteries by draining them to 0V. Once the load went away, the power supply came back. Then the load turned on again. Then tripped the overcurrent again, etc. etc. I believe @NateMieras is right. Turn the overcurrent knob all the way up and see what happens. It may not be a linear pot.
I agree with some other commenters. You got this supply at a very good price. Parts for these are not all that expensive and if you fixed it, you would have a great power supply well under what you could purchase a new or used working supply. I have a 35 M and it's been a great supply. Mine will most likely be passed down to the next generation when I'm worm food. These are not all that hard to work on. Think twice before returning it. P.S. You're one of the more technical dudes on H.R. TH-cam. Show us what you got. You can do it !!!!!
I got the 35 based off its strong reputation and I would like to repair the PS but I want to find out if this actually worked and get some sort of refund.
11:35 hope you would have talked about the crow bar circuit and why it’s important to use & have one in your supply 😉my buddy zorched his hf rig n meter and a 2m rig using a Lamda supply which outputted 60v into his gear. I was using a 45amp bulldog switching but upgraded to a vs35 m too but paid 2x and got it new. One complaint is these got hot with no fan so I added a 120mm high output fan to keep it happier 😊
Hey Kevin. I meant to cover it but ended the video early when it started to act crazy... hopefully I can work out a deal with the seller and then attempt to get this sorted out.
Fortunately these power supplies are very simple, a lot of people have run these for decades continuously but a few simple modifications can improve them. Very easy to repair, A few design weaknesses that are very simple to address, I did notice you had the current limit set low unless that was just the camera angle. I always keep an eye out for a cheap faulty one, about the worst failure (other than the meters) can be the transformer, yours is OK so could be repaired in a very short time at very low cost.
I have to RS-35M model, with meter but not variable. It's been my workhorse for years. I was leery of the terminals too. Also, watch out for those transistors on the back. The case isn't the ground, it's live voltage, so if you accidently drop something on them it will short out big time. I found some covers for both the connectors and transistors on Thingiverse and printed them out.
These are really good supplies quiet and robust. I do think 150 is a little high I think 100-125 would be all I would pay for a used supply. I use the newer more modern one in my shack and it has been reliable for a switching supply, so far so good mine is about 20 years old. 😊
I thought most people reduced their output power for digital modes because the transmitters will get hot at high duty cycles. Thus less current from the supply continious also. I got the meterless version and it is used. All I can say is it does hum just a little but not an issue. I cannot imagine it costing much to repair one of those unless it needed a transformer, and it would not be too difficult to troublehoot.
I have been using The same VS35M for almost 30 years now that I bought from AES . The only trouble I had was the voltage pot went bad and I replaced it 20 - 25 years ago. The pass transistors on the one you bought do not appear to be original and someone has worked on the regulator board at some point in it's life. You paid a premium for it IMHO and hopefully the seller will work with you. If the seller doesn't then it gives you a great canvas for some linear PSU repair content. When life gives you lemons make whiskey sours :) That supply repaired will likely remain serviceable for the rest of your life. Thanks for sharing !
@@TheSmokinApe Cool beans it is a great PSU if you choose to save it. Playing devil's advocate here but I imagine the seller never put it under load. In my experience a 10 amp load on a PSU rated 10 amps or greater is a really good test like you demonstrated. I use an enormous 1ohm load here and the lion's share of failure I have seen in PSU testing rated equal to or greater than the load I present has occurred in the 5-10 amp range. If it survives big Sid it is good to ride the river with.
I have Had Several Astron Power suplys over the years & I Still Use one Every Day..I Prefer the ones with out the A adjustment (just Causes Problems IMHO) But I Do Like The Meters & V Adjustment..I Run a Yaesu FT-991 a Icom IC-4100D & a Retivis RA-25 From a Astron RS 20A Daily ! These Things Are Just Tanks IMHO ! I Tried Switchers Back Years Ago and had Nothing But Trouble from Them & I have Also Ran a Lot of Pyramid PS36KX They Just Will Not Hold Up like The Astron's do ! Just some of what i Have saw & Learned in my 35+ Years messing with Electronics & being a repair Guy ! Always Buy Astron PS if ya want Quality ! a switcher if ya like junk or Pyramid if ya dont use them very much & at about 1/4 what they are rated at..lol.
Reminds me I should probably replace the capacitor in my 20 year old Astron 35M linear power supply. It's run fine for over 20 years with only the on/off switch needing replacement in 2011.
Mr. Carlson’s Lab did a video repairing one of those. Do a search. I have an RS-35M and am going to replace the whole board and transistors in the back. Keep the PS and get some repair of these under your belt. You won’t regret it. Take care.
Ape, you’ve got mad gorilla skills, astron parts are easy to get, you can fix it even with your soldering ability 😉 Of course try for that partial refund too.
Fixing the power cord would be the least of my worries since it is probably one of the easiest repairs you can make on most equipment. One thing I am wondering about.... is there a conversion kit/instructions to add the variable voltage and current knobs to a RS-35M? I will have to look into that.
Hey Ryan, you are right about the cord. I am not sure about the kit but that shouldn't be too bad either, I am pretty sure the schematics are available online.
@@TheSmokinApe Thanks for the reply. As I am finally venturing into HF for the first time, the non-variable version of this amp is what I will use. Just so it is clear in my head.... would not having any adjustents be detrimental to doing digital modes? FT8, Olivia etc?
have fixed a lot of power supplies threw the years.Astron being one of the easiest to fix and heavy duty. A few test points will show the problem . start with voltage on filter cap. then the output of reg board to base of pass transistors. also check current limit pot. a big clue is the heating of pass transistors on heatsink. I use a inferred camera . heat sensing type. easy check diodes and transistors. bad connection's show right up. my useful tool as a electrician . I got a basic one for free at a repeater cite.Think the RS 35. no meters no pots. has not been on in 10 years. tested fine. multi repeaters at a cite. I was working on a GMRS up-grade. better coax. better lightning protector. better duplexer. gained 20% more power at antenna. took a nearbuy hit. lost coverage area. got new AGM battery installed as well. now we have back up power supply. astron has a supply with battery back up . got that at outher repeater cite. parts also can be gotten Newark electronics or mouser. they use LM723 ic. no socket on astron. always add MOV or GDT to them . I got a RS70 and RS-50 in my shop. and home made ones. 200amp . adj 14V . just 4 50 amp transformers. 35 pass transistors. 2N3772. bult in 1988. it's big. 73's
I have had a couple of these over the years. It sure looks like someone was inside at one time, maybe troubleshooting the problem you were showing. Just thinking out loud, I wonder if changing the current limit control up higher, would make a difference? I see you had it set for about half of the knob's travel, and i don't remember how linear the adjustment is... if that don't help, it could be the LM723, I have had to replace a couple of them in the past. That's the regulator chip, and just doing a quick search, it looks like they go for $2 or $3. If the chip develops a thermal issue in the current regulator, that could be what you were looking at, or something in the feedback for the regulator. I guess though if you are going to try to return it to the seller, then all this don't matter.. Better luck at the flea mkt next time!
@@TheSmokinApe Before replacing the regulator board, make sure those 4 pass transistors are performing as they should. They may be breaking down under load conditions. Does the goop (aka silicon heat sink grease) under them appear to be fresh?
Ape, from past experiences, I always check to make sure the proper fuse is in the unit before powering on. Not telling you what to do, you probably did that, but you didn't mention it so I thought I would bring it up. I have a 35M and had to replace one of the meters. Astron sent me an LED version with the resistor kit. It was like $24.00. I'll replace the other one too only because it looks silly with only one meter lit. In the past, I always covered the output of the supply with a cheap plastic project box. While you have the cover off, pound out that dent. LOL I'm glad I waited until the end of the video before hitting the send button. Let us know how it turns out with the seller.
@@TheSmokinApe the heat sink is only adequate and was suggested to be beefed up a little. Yes, even if you have to replace one or two of the transistors in the back by the heatsink, it's still cheaper than buying new
Great video, thanks for sharing. I'm also interested in what you find out, if you get a refund, what you do/did to repair it, etc. I have a Astron RS-35A, so no meters or adjustments. I like it a lot.
I would take time to rebuild the hole unit. This way, we all know that it's not going to kill your equipment, and it will help keep your mind at ease. Waven from Southern California
good vid, currently considering if linear supply is worth the money. I already have enough noise at my qth and i've heard good and bad things about switching power supply noise. I've owned neither kind, i'm all battery right now and thats getting old. Lets go ahead and do it anyway. HAHAHAHA! Yes.
Astron has never been known for light weight power supplies! But they are tanks and I know people who have had them since the 70's and they still work fine today.
@@TheSmokinApe Is the battery tester you used Lifpo4 specific? That would cause the effects you were seeing. I have no experience with those battery testers. Wire up a 1ohm 100 watt resister in series with a test meter and watch the current draw. It may give a different result. Those older supplies react a lot different than a switching power supply. If it's getting any pulses from the battery tester ( Like I said I have no experience with them ) , it could cause the bridge rectifier to act funny. Or I could be blowing smoke out my ass. I haven't been able to do my own work for a number of years now I shake so bad that I think I've forgotten most of what my father taught me through the 60's, 70's, and 80s!
Hey VE9SY, the tester has a power supply setting. I was messing with it again today and got better results. I am thinking the pot may be screwy but that's just a guess at this point.
Hey, I was watching where you had the AMPS knob on the ASTRON. It was at 12 noon. can you rotate that to fully clock-wise until it stops at MAX and run test again?
Nice video, thank you for sharing. I watch and enjoy your style and explanations very much. Since you are talking power supplies, I wanted to point you to a video on grounding I came across which is the best I have seen. It is VERY worth watching the entire video, but the part I wanted to point you too is at about 24 minutes in. The guy describe why you want to remove the voltage negative from the case grounding. Take a look and see what you think. I will make this change to my Astron switching mode PS at this point if I can ever find the actual schematic. Apparently it's a secret to national security issue or something. lol
Interesting article on this PS - Might shed some light. people.ohio.edu/postr/bapix/Astron_VS-35M.htm Ape, how do you determine where to set the AMPS knob (Current limiting)?
Astron supplies are the easiest power supplies to repair, I buy them whenever they seem affordable. Repairing them cost pennies and even the transformer is not that expensive. I have replaced several of them with torroidial surplus transformers in the past. one thing I noticed is that some models have a extreme fast loop speed so if you run SSB peaks one would trigger either over voltage or over current. Slowing down the feedback loop(s) with a small 0.1 -1uf capacitor prevents this from happening.
Thanks for the info, and for watching.
Ape, I use a variable carbon pile load (Harbor Freight) to test the full output of these large supplies. Often times there is a problem with the Astron's where there is a current sense resistor of the incorrect value. That makes the supply "fold back" when the load is less than the rated amps of the supply. The Astron schematic is available online and all the supplies are basically the same. Keep a few of the voltage regulator chips on hand (I tape one inside the supply) for easy replacement when they go bad.
73 Bro.
I like that Carbon Pile idea! Yeah, these seem like lego sets and should be pretty easy to fix. Thanks Hollywood 👍
I wish you good luck with your Astron PS. I never had good luck with them and will never buy another. As noted by the previous comments they're easy to work on (whats not said is 'that's because they need to be'). In my last job as an Electronics Repairman for towboats on the inland waterways (mostly marine FM VHF and HF SSB radios) I had to repair tons of them. I always attributed that to the generators on the boats... But found out after I bought a 35M for my shack that's not always the case. A couple of months in the LM723 regulator went out while I was gone and not operating, so I replaced it (socketed) and didn't bother with warranty. Right after the warranty expired the transformer shorted turning the fuse (and several after while troubleshooting) into flashbulbs, again on but not being loaded (no thunderstorms were around or other electrical damage in my home, its MOV was good). When the MOV is disabled and all the output leads are loose and isolated there's no doubt what it is. I now consider Astron's a Hobby PS. For me at least, they are a hobby in their own right to keep running. I'm retired now and look for reliability over a continuing project. The PS I'd built before the 35M was a Tank that never gave problems (gave it to a new ham). I have heard other 723 based PS's can have problems also, so I just got a Yaesu FP-1030A ($230 new) for its good reputation and lack of 723. Time will tell. I refuse to use switching PS's for my rigs. YMMV! (BTW the few Icom Xfmr PS's I saw on the boats were very reliable) 73's mike - N4ONL (The 35M will be parted our or a basis for another Tank some day, sans regulator board)
Well dang, that ain't encouraging. Thanks for the info, much appreciated...
As I Said YMMV! Several folks seem to have no problems with them. Also after Astron added the RF bypass cap to the output, the crowbar wouldn't trigger as easily from RF. I can't remember what output transistors they use, I think it used to be 2N3055's but I could be wrong, I always replaced bad output(s) with sets of 4 x 2N3772's which have a higher rating. You may get decades of trouble free use out of yours, I hope you do!
73's mike - N4ONL
It looks like the current limit kicked in causing those voltage swings. Try running the test again with the current knob fully clockwise and give er the beans. I bet you'll be good.
I'd think that at 1/2 way it should do more than 3A, but in either case I'd expect that the voltage may dip but not swing like that. Thanks for the comment Nate 👍
@@TheSmokinApe I agree with you that I'd expect it to do more than 3A half way. I wonder if it's not a linear adjustment.
I've used linear power supplies in school which would "flicker" between full output voltage and zero when they hit the current limit. I wouldn't have believed it had I not seen it myself.
Let's test it out, son! Looking forward to the next video.
That exactly the same way mine acts when I have the current knob turn down and it reaches cut off.
@@TheSmokinApe Hi Ape. I believe the supply was acting exactly how it should. The current knob is an overcurrent limit setting. So when the load hit that limit, the supply just shutoff. I suspect that when the load tester saw the voltage go away, it shutoff the load. It probably has a minimum voltage limit so it doesn't damage batteries by draining them to 0V. Once the load went away, the power supply came back. Then the load turned on again. Then tripped the overcurrent again, etc. etc.
I believe @NateMieras is right. Turn the overcurrent knob all the way up and see what happens. It may not be a linear pot.
I agree with some other commenters. You got this supply at a very good price. Parts for these are not all that expensive and if you fixed it, you would have a great power supply well under what you could purchase a new or used working supply. I have a 35 M and it's been a great supply. Mine will most likely be passed down to the next generation when I'm worm food. These are not all that hard to work on. Think twice before returning it. P.S. You're one of the more technical dudes on H.R. TH-cam. Show us what you got. You can do it !!!!!
I got the 35 based off its strong reputation and I would like to repair the PS but I want to find out if this actually worked and get some sort of refund.
11:35 hope you would have talked about the crow bar circuit and why it’s important to use & have one in your supply 😉my buddy zorched his hf rig n meter and a 2m rig using a Lamda supply which outputted 60v into his gear. I was using a 45amp bulldog switching but upgraded to a vs35 m too but paid 2x and got it new. One complaint is these got hot with no fan so I added a 120mm high output fan to keep it happier 😊
Hey Kevin. I meant to cover it but ended the video early when it started to act crazy... hopefully I can work out a deal with the seller and then attempt to get this sorted out.
Fortunately these power supplies are very simple, a lot of people have run these for decades continuously but a few simple modifications can improve them. Very easy to repair, A few design weaknesses that are very simple to address, I did notice you had the current limit set low unless that was just the camera angle. I always keep an eye out for a cheap faulty one, about the worst failure (other than the meters) can be the transformer, yours is OK so could be repaired in a very short time at very low cost.
He G0FVT, I am trying to get a partial refund so I can attempt a repair based off the points you make. Thanks for the comment 👍
I’m looking for a used R35a-ap. I don’t want varable voltage but would prefer Power Pole connector. I will switch to Power Pole connectors if needed.
I was thinking about doing a power pole mod on this one 🤔
I have to RS-35M model, with meter but not variable. It's been my workhorse for years. I was leery of the terminals too. Also, watch out for those transistors on the back. The case isn't the ground, it's live voltage, so if you accidently drop something on them it will short out big time. I found some covers for both the connectors and transistors on Thingiverse and printed them out.
Hey Ron, I am thinking about replacing the posts with 5 way posts.
I have that very same model. It runs 24/7 unless we have a power failure. Very solid power supply.
Hey TUH, I am sure this one will get sorted out...
@@TheSmokinApe I'm sure you will. Thanks for another interesting video
These are really good supplies quiet and robust. I do think 150 is a little high I think 100-125 would be all I would pay for a used supply. I use the newer more modern one in my shack and it has been reliable for a switching supply, so far so good mine is about 20 years old. 😊
Hey James, it was actually 110$ and about 25$ in shipping... Thanks for watching.
I thought most people reduced their output power for digital modes because the transmitters will get hot at high duty cycles. Thus less current from the supply continious also. I got the meterless version and it is used. All I can say is it does hum just a little but not an issue. I cannot imagine it costing much to repair one of those unless it needed a transformer, and it would not be too difficult to troublehoot.
Check the current control it is probably set too low and the voltage output is folding back,set the current control to max for the test.
Thanks Coltronex!
I have been using The same VS35M for almost 30 years now that I bought from AES . The only trouble I had was the voltage pot went bad and I replaced it 20 - 25 years ago. The pass transistors on the one you bought do not appear to be original and someone has worked on the regulator board at some point in it's life. You paid a premium for it IMHO and hopefully the seller will work with you. If the seller doesn't then it gives you a great canvas for some linear PSU repair content. When life gives you lemons make whiskey sours :) That supply repaired will likely remain serviceable for the rest of your life. Thanks for sharing !
Hey SC. I am trying to work something out with the seller as I would prefer to keep it...
@@TheSmokinApe Cool beans it is a great PSU if you choose to save it. Playing devil's advocate here but I imagine the seller never put it under load. In my experience a 10 amp load on a PSU rated 10 amps or greater is a really good test like you demonstrated. I use an enormous 1ohm load here and the lion's share of failure I have seen in PSU testing rated equal to or greater than the load I present has occurred in the 5-10 amp range. If it survives big Sid it is good to ride the river with.
@@survivalcomms yeah, I suspect he just powered it on and thought it was good
@@TheSmokinApe That is par for the course :)
I've repaired a couple of these. Caps mostly. As noted, they are built like tanks and are very easy to work on. I'm always looking for these!
Yeah, the seem very serviceable. Thanks for the comment 👍
I have Had Several Astron Power suplys over the years & I Still Use one Every Day..I Prefer the ones with out the A adjustment (just Causes Problems IMHO) But I Do Like The Meters & V Adjustment..I Run a Yaesu FT-991 a Icom IC-4100D & a Retivis RA-25 From a Astron RS 20A Daily ! These Things Are Just Tanks IMHO ! I Tried Switchers Back Years Ago and had Nothing But Trouble from Them & I have Also Ran a Lot of Pyramid PS36KX They Just Will Not Hold Up like The Astron's do ! Just some of what i Have saw & Learned in my 35+ Years messing with Electronics & being a repair Guy ! Always Buy Astron PS if ya want Quality ! a switcher if ya like junk or Pyramid if ya dont use them very much & at about 1/4 what they are rated at..lol.
Thanks for the info BigChew 👍
Reminds me I should probably replace the capacitor in my 20 year old Astron 35M linear power supply. It's run fine for over 20 years with only the on/off switch needing replacement in 2011.
I still need to check the cap in this one. Thanks for checking out the video MrRadio 👍
Mr. Carlson’s Lab did a video repairing one of those. Do a search. I have an RS-35M and am going to replace the whole board and transistors in the back. Keep the PS and get some repair of these under your belt. You won’t regret it. Take care.
Thanks for the info about Mr. Carlson 👍
Ape, you’ve got mad gorilla skills, astron parts are easy to get, you can fix it even with your soldering ability 😉 Of course try for that partial refund too.
Thanks man 👍
Fixing the power cord would be the least of my worries since it is probably one of the easiest repairs you can make on most equipment. One thing I am wondering about.... is there a conversion kit/instructions to add the variable voltage and current knobs to a RS-35M? I will have to look into that.
Hey Ryan, you are right about the cord. I am not sure about the kit but that shouldn't be too bad either, I am pretty sure the schematics are available online.
@@TheSmokinApe Thanks for the reply. As I am finally venturing into HF for the first time, the non-variable version of this amp is what I will use. Just so it is clear in my head.... would not having any adjustents be detrimental to doing digital modes? FT8, Olivia etc?
Nah, you should be fine
have fixed a lot of power supplies threw the years.Astron being one of the easiest to fix and heavy duty. A few test points will show the problem . start with voltage on filter cap. then the output of reg board to base of pass transistors. also check current limit pot. a big clue is the heating of pass transistors on heatsink. I use a inferred camera . heat sensing type. easy check diodes and transistors. bad connection's show right up. my useful tool as a electrician . I got a basic one for free at a repeater cite.Think the RS 35. no meters no pots. has not been on in 10 years. tested fine. multi repeaters at a cite. I was working on a GMRS up-grade. better coax. better lightning protector. better duplexer. gained 20% more power at antenna. took a nearbuy hit. lost coverage area. got new AGM battery installed as well. now we have back up power supply. astron has a supply with battery back up . got that at outher repeater cite. parts also can be gotten Newark electronics or mouser. they use LM723 ic. no socket on astron. always add MOV or GDT to them . I got a RS70 and RS-50 in my shop. and home made ones. 200amp . adj 14V . just 4 50 amp transformers. 35 pass transistors. 2N3772. bult in 1988. it's big. 73's
Great info Robert, thank you for sharing 👍
Hi ,how have you got the current limit set ?
Dave
I had it set to high noon, I did mess with it but I wouldn't expect the voltage to swing like that if that was the issue.
Nice looking PS Ape, too bad it didn't pass the test, easy to change the plug if needed.
I think it has bigger problems 👀
I have had a couple of these over the years. It sure looks like someone was inside at one time, maybe troubleshooting the problem you were showing. Just thinking out loud, I wonder if changing the current limit control up higher, would make a difference? I see you had it set for about half of the knob's travel, and i don't remember how linear the adjustment is... if that don't help, it could be the LM723, I have had to replace a couple of them in the past. That's the regulator chip, and just doing a quick search, it looks like they go for $2 or $3. If the chip develops a thermal issue in the current regulator, that could be what you were looking at, or something in the feedback for the regulator. I guess though if you are going to try to return it to the seller, then all this don't matter.. Better luck at the flea mkt next time!
Hey Arnold, if I do end up keeping it I will probably replace the whole regulator board.
@@TheSmokinApe Before replacing the regulator board, make sure those 4 pass transistors are performing as they should. They may be breaking down under load conditions. Does the goop (aka silicon heat sink grease) under them appear to be fresh?
Nah, it looks old.
@@TheSmokinApe That makes me very suspect of them. Just sayin'.
Ape, from past experiences, I always check to make sure the proper fuse is in the unit before powering on. Not telling you what to do, you probably did that, but you didn't mention it so I thought I would bring it up. I have a 35M and had to replace one of the meters. Astron sent me an LED version with the resistor kit. It was like $24.00. I'll replace the other one too only because it looks silly with only one meter lit. In the past, I always covered the output of the supply with a cheap plastic project box. While you have the cover off, pound out that dent. LOL I'm glad I waited until the end of the video before hitting the send button. Let us know how it turns out with the seller.
I made sure these was a fuse but didn't check the value, thanks for that idea! I am going to ask for a partial refund and order some "parts" 👍
@@TheSmokinApe From what others have told me, the heat sink in the top (or bottom) of the circuit board is only
@@TheSmokinApe the heat sink is only adequate and was suggested to be beefed up a little. Yes, even if you have to replace one or two of the transistors in the back by the heatsink, it's still cheaper than buying new
Thanks for the info!
design and print a cap that will slide over those lugs in the back to keep them from being shorted out.
If only I knew a designer...
Hi just wondering why you don't run a battery setup instead of a power supply
I actually do both 👍
@@TheSmokinApe Gotcha! Do you have a vid of your battery setup by any chance?
I do not, but have it on the list
That's too bad. I have 2 Astron 35Ms that I bought used and both have been working great.
Well, I was hoping this one would work great too 🙁
Great video, thanks for sharing. I'm also interested in what you find out, if you get a refund, what you do/did to repair it, etc. I have a Astron RS-35A, so no meters or adjustments. I like it a lot.
Thanks William!
I would take time to rebuild the hole unit. This way, we all know that it's not going to kill your equipment, and it will help keep your mind at ease. Waven from Southern California
I think that’s sound advise Michael 👍
good vid, currently considering if linear supply is worth the money. I already have enough noise at my qth and i've heard good and bad things about switching power supply noise. I've owned neither kind, i'm all battery right now and thats getting old.
Lets go ahead and do it anyway. HAHAHAHA! Yes.
If you are getting noise from the battery there might be something else causing the noise. Thanks for the comment 👍
@@TheSmokinApe oh no no not the battery lol, just the area i live.
@@youtubeaccount931 gotcha
You mentioned last week you have a SunSDR, when are you going to do a video on that radio?
He has had it for a while and I keep asking him that ;)
lol, it's on the list...
Astron has never been known for light weight power supplies! But they are tanks and I know people who have had them since the 70's and they still work fine today.
I am going to see about a partial refund and see if we can get this think working. Thanks for watching VE9SY 👍
@@TheSmokinApe Is the battery tester you used Lifpo4 specific? That would cause the effects you were seeing. I have no experience with those battery testers. Wire up a 1ohm 100 watt resister in series with a test meter and watch the current draw. It may give a different result. Those older supplies react a lot different than a switching power supply. If it's getting any pulses from the battery tester ( Like I said I have no experience with them ) , it could cause the bridge rectifier to act funny. Or I could be blowing smoke out my ass. I haven't been able to do my own work for a number of years now I shake so bad that I think I've forgotten most of what my father taught me through the 60's, 70's, and 80s!
Hey VE9SY, the tester has a power supply setting. I was messing with it again today and got better results. I am thinking the pot may be screwy but that's just a guess at this point.
"Constant 3.8v for amateur radio"? Lol
That slipped past QC review. Lol
Get T.O to fix it on a video.😊
D'oh! I meant to say 13.8! Get T.O. to fix the video on the video?
Good test. Sorry it didn't work out
I’m very don’t some work on it and have been using it a little 👍
Love my astron rs-35m paid 50 dollars tank
50$ is a great deal 👍
Always like your videos where you "deep-dive" into some piece of gear. Great job Ape!!! 🙂
Hey, I was watching where you had the AMPS knob on the ASTRON. It was at 12 noon. can you rotate that to fully clock-wise until it stops at MAX and run test again?
I think something may be screwy with that knob, I was messing with it again today and got better results.
Nice video, thank you for sharing. I watch and enjoy your style and explanations very much. Since you are talking power supplies, I wanted to point you to a video on grounding I came across which is the best I have seen. It is VERY worth watching the entire video, but the part I wanted to point you too is at about 24 minutes in. The guy describe why you want to remove the voltage negative from the case grounding. Take a look and see what you think. I will make this change to my Astron switching mode PS at this point if I can ever find the actual schematic. Apparently it's a secret to national security issue or something. lol
Hey Vincent, who posted that video?
@@TheSmokinApe Ham Radio TV youtube channell is where I saw it.
Ah, I know him. Thanks!
Rectifyers transistors
Looks to be a problem on the regulator board.
Yeah, I should probably swap that out 😕
@@TheSmokinApe If you can get just the board, that maybe the way to go! They make good power supplies. Don't junk it, fix it!
Bummer. Good luck for the refund. Not sure where you got this, but this is the kind of risk we take buying from hamfests and flea markets.
Thanks W1TEA!
You should not be overwhelmed if one needs repair. Only if someone sold it to you as 100% and it has issues, then you can be piffed off.
I’m not Tom and thank you for the encouragement 👍
First! I'm lit, just sayin.
I think you are second 🤨
What a bummer man.
Yeah, I am asking for a discount and then I will see about a repair job. We'll see...
ape, let us know if he gives the money back...
Will do...
That stinks.
yes
Interesting article on this PS - Might shed some light. people.ohio.edu/postr/bapix/Astron_VS-35M.htm Ape, how do you determine where to set the AMPS knob (Current limiting)?
Thanks for the link Alan. I'd expect the voltage to be more stable if it was a result of the current pot, it shouldn't swing like that.
I'd like to know how you determine where to set the amp knob too! I just got a used Astron VS-35M.