Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

donate to eham
   Home   Help Search  
Pages: Prev 1 [2] 3 4 5 Next   Go Down
  Print  
Author Topic: Is Astron still king?  (Read 2323 times)
SOFAR
Member

Posts: 1447




Ignore
« Reply #15 on: July 17, 2019, 10:55:31 AM »

http://www.repeater-builder.com/astron/astron-intro-stuff.html
Logged
K0UA
Member

Posts: 4352




Ignore
« Reply #16 on: July 17, 2019, 01:11:42 PM »

Ok, after calling 1A0C (SMOM) for well over an hour continuously on 20 meter FT8, my Switcher 50 amp supply's fan JUST kicked on. I had felt of the case a few minutes earlier and the fan in the 7610 had been running continuously for some time, but the rig is staying cool to the touch up top, and the power supply was getting warm.  The fan just now kicked off.. By golly there really is a fan in the thing AND it really works. The case is barely warm now. I was beginning to wonder if the fan really worked in the thing, because I have had it for over a year and never heard it.  By the way the pileup for this DX entity is rather severe. And I am NOT giving up.  Smiley

OH, as a postscript on my linear Astron 35M supply I now have over on the test bench, when I would push it hard it would get so hot you didn't want to leave your fingers on the heatsink for any length of time. so I put two 24 volt muffin fans in series on the heatsink to keep it cool.  They ran so silently like that at a reduced speed you could hardly hear them. BUT linear supplies do get hot when pushed and the 35M could profit from some fans. Linear supplies are not nearly as efficient as switchers so more heat is thrown off. I am not sure how old my 35M is but it is old.  I replaced the goofy inside the meter lamps with LED's and dropping resistor, modifying the circuit board and feed.  They look better than they ever did before.  I should have made a video of it. The key is to grind the lens off of the LED so it disperses light better instead of spotlighting. This procedure was not super easy, but the results are spectacular.
« Last Edit: July 17, 2019, 01:18:11 PM by K0UA » Logged

73  James K0UA
ARRL Missouri Technical Specialist
KE6EE
Member

Posts: 2788




Ignore
« Reply #17 on: July 17, 2019, 01:48:31 PM »

The key is to grind the lens off of the LED so it disperses light better instead of spotlighting. This procedure was not super easy, but the results are spectacular.

Interesting observation especially for one who has the prospect of replacing some meter lamps.

Would a super easy alternative be simply to put a dot of high temperature paint on the apex of the LED?
Logged
G3RZP
Member

Posts: 1224




Ignore
« Reply #18 on: July 17, 2019, 02:10:27 PM »

Switching PSUs have more parts, so would in theory have a lower MTBF than Linear supplies. But when it comes 100 watt + supplies, the linear will usually run hotter and thus reduce the MTBF. So just where is the cross over point? In practice, I suspect that it is more of a cross over cloud, depending on what make of linear  and what make of switcher......

The usual Yes/No/maybe of much electronics....
Logged
K0UA
Member

Posts: 4352




Ignore
« Reply #19 on: July 17, 2019, 09:03:18 PM »

The key is to grind the lens off of the LED so it disperses light better instead of spotlighting. This procedure was not super easy, but the results are spectacular.

Interesting observation especially for one who has the prospect of replacing some meter lamps.

Would a super easy alternative be simply to put a dot of high temperature paint on the apex of the LED?

I am not sure, but it was the taking the meter apart that wasn't much fun, the grinding of the lens off wasn't hard, I used a dremel with a cutting wheel to remover a bunch of it, and then ground it to squar it up a bit.  Anyway when done the lens was gone and a frosty flat surface was left.  This worked great.  Of course this is AFTER I put the LED's in without doing this and had two spotlight's behind the meter face.. NOT pretty at all. But the ground down one's really look even an professional.  Still getting the meters out (one is hard behind transformer) and cracked apart and worked on and then put back together and in was the real work. The LED's were no big deal, IF you had brains enough to do it in the first place instead of putting the LED's in whole.
Logged

73  James K0UA
ARRL Missouri Technical Specialist
N8FVJ
Member

Posts: 866




Ignore
« Reply #20 on: July 18, 2019, 04:49:48 AM »

The  Astron linear power supply is so simple, it does not need any update. It has much less parts vs switching power supplies. It uses high current 2N3771 transistors vs the weaker 2N3055 and a generous sized heat sink. The transformer is adequately sized and uses a filter capacitor of sufficient size (computer grade). That is the only criteria of a good design.
Logged
VA3VF
Member

Posts: 2861




Ignore
« Reply #21 on: July 18, 2019, 05:33:16 AM »

I don't know if Astron is still king.

I have been using a Samlex SEC-1223 for 10 years or so now, never a problem.

Last month Amazon had the much maligned Pyramid PSV300 on sale for around $50. I took a chance, and so far it has been great. Actually better than the Samlex, due to its higher current rating.

I used to have a Pyramid linear PS as well. Again, never a problem. Sold it after I bought the Samlex.

Longevity is impossible to predict but as of today the PSV300 was a good buy, excellent at $50.
« Last Edit: July 18, 2019, 05:48:20 AM by VA3VF » Logged
K0UA
Member

Posts: 4352




Ignore
« Reply #22 on: July 18, 2019, 05:49:43 AM »

I have noticed older men are gravitating towards the switching power supply's. Let the younger men have the "old iron". I think it may have something to do with gravity...  Smiley
Logged

73  James K0UA
ARRL Missouri Technical Specialist
N2AYM
Member

Posts: 145




Ignore
« Reply #23 on: July 18, 2019, 05:55:47 AM »

The  Astron linear power supply is so simple, it does not need any update. It has much less parts vs switching power supplies. It uses high current 2N3771 transistors vs the weaker 2N3055 and a generous sized heat sink. The transformer is adequately sized and uses a filter capacitor of sufficient size (computer grade). That is the only criteria of a good design.

On the contrary - many of the older Astrons lack the automatic reset circuit and must be reset manually after a power surge, see below.

http://www.repeater-builder.com/astron/astron-ovpr-12.html
Logged
VA3VF
Member

Posts: 2861




Ignore
« Reply #24 on: July 18, 2019, 06:01:41 AM »

I have noticed older men are gravitating towards the switching power supply's. Let the younger men have the "old iron". I think it may have something to do with gravity...  Smiley
'Gravity', the main reason I switched (no pun intended) from a linear to a switching PS.
Logged
K0UA
Member

Posts: 4352




Ignore
« Reply #25 on: July 18, 2019, 06:31:28 AM »

I have noticed older men are gravitating towards the switching power supply's. Let the younger men have the "old iron". I think it may have something to do with gravity...  Smiley
'Gravity', the main reason I switched (no pun intended) from a linear to a switching PS.

Sure, no pun intended... uh-huh..
Logged

73  James K0UA
ARRL Missouri Technical Specialist
KE6EE
Member

Posts: 2788




Ignore
« Reply #26 on: July 18, 2019, 10:17:07 AM »

It was the taking the meter apart that wasn't much fun, the grinding of the lens off wasn't hard

That makes sense! Thanks for clearing that up.
Logged
K5DH
Member

Posts: 69


WWW

Ignore
« Reply #27 on: July 18, 2019, 11:38:29 AM »

I use an Astron RS-35M to power my station.  I bought it new in 1983.  It's the only supply I've owned since then.  The only repair I've had to do was to replace the on/off rocker switch many years ago.  Does the unit get warm when used heavily?  Probably, but I honestly don't know.  I've never bothered to reach back there and check, because I've never worried about how well it would hold up.  There has never been a question.  Like the old Timex watches, "It takes a licking and keeps on ticking".  In the unlikely event that it ever fails, I know I can repair it.  The circuit is classic and simple, and there are no "magic" parts in there.  Yes, the supply is big and heavy, but I have the space for it and I don't have much need to move it around.  It sits on its shelf and does its thing.  Decade after decade. 

Buy the best.  You won't regret it. 
Logged
K8AXW
Member

Posts: 7036




Ignore
« Reply #28 on: July 18, 2019, 12:10:22 PM »

Astron still King?  As far as I'm concerned they still are.

IQ sums it all up as tidy as you can make it.  I would like to emphasize one thing though.

If it ever craps out it's easy to work on and the parts are inexpensive.  I have a switcher, which if it goes bad hits the garbage can.

I just acquired an Astron RS-35M which I have lusted after for years  but couldn't afford it. The inside is beautiful!
Logged

A Pessimist is Never Disappointed!
W8JJI
Member

Posts: 358




Ignore
« Reply #29 on: July 18, 2019, 12:33:14 PM »

Astron's -linear- power supplys are hard to beat.
Logged
Pages: Prev 1 [2] 3 4 5 Next   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!