开云体育

Any of the TE grade ones built by HP. Even their economy class small
green plastic cased ones are better than the econo class Chinese meters.
Lambdas are also good but not as EASY to find service info on as just about
ANY of the HP PSs are.. Most of the other US built PSs built by any of the
major TE manufacturing companies are also good but none tops HP in terms of
reliability, durability, and the level of service information available. I
have at least one HP PS built in 1966 that is still running strong and has
never been recapped or had to be repaired. Needless to say that is a linear
supply and there's no digital electronics in it and it's HEAVY but as any
experienced machinist can tell you, HEAVY means that it's built to last.

True story, a few years ago a EE student at a nearby college rented a
room in a house next door to me and we became friends. He was an avid
electronic hobbyist with the arduinos but lacked any reaperience in
electronics in general and he was also poor as most students are. He needed
PSs, meters and other parts for his arduino projects but he couldn't afford
them. He'd never heard of a hamfest so I took him to several of them and he
was like a kid in a candy store! He had never imagined that TE and parts
could be bought so cheaply! I also took him to an electonics scrap yard
that is owned by a friend of mine. He walked out of there with THREE old
HP 54100 color scopes! My friend took pity on him and only charged him what
he thought that the scopes were worth in scrap value, $35. My neighbor
later told me that he got two of the three scopes completely working just
by disassembling and cleaning the tiny mechanical attenuator switchs in
them. But on the way out of the scrap yard, I looked over at one of the
scrap baskets and spotted an old Lambda power suply. I can't tell you what
model it was but it was a heavily built linear supply with dual analog
meters on the front and it had variable voltage and variable current
limiting and went to about 30 VDC. It had been sitting in the scrap yard
for MONTHs and was nasty looking but I pointed it out to him and said
"Here. This is what you need for your projects." He took one look at it and
thought that I was joking and that it would never work.I But I told him
that I was serious and that I would BET that it worked. He carried it home
and later that day he called me and in an amazed voice that "It works!".
He graduated several years ago and moved away but we still talk
occasinonally and just a few months ago he told me that he is STILL using
that PS and that it is still working fine. In my experience, I don't think
that I've ever found or seen a Lambda PS that didn't work!

On Sat, May 1, 2021 at 10:28 PM Harvey White <madyn@...> wrote:

What would you consider good power supplies given what you've said?

Harvey


On 5/1/2021 9:37 PM, - wrote:
> "Be worth obtaining an adjustable power supply if you plan on doing many
> board repairs. Why risk damaging boards?"
>
> Absolutely! And use a PS with an adjustable current limit and set the
> limit only slightly higher than the amount of current that you expect the
> item under test to draw. I used to keep notebooks full of notes about
> various repairs including how much power that model item actually drew
> under various operating conditions. I also STRONGLY suggest using a GOOD
> quality PS like those from HP, Lambda, etc and not one of cheap Chinese
> ones. Many of the cheap PSs contain large filter caps on their output in
> oder to reduce AC ripple but those large caps can provide enough power to
> fry your electronics before their *slow* current limiters can kick in.
> GOOD PSs are expensive when new but used ones are available just about
> anywhere (at least in the US and Canada) and are usually very cheap
(~$20)
>
> On Sat, May 1, 2021 at 8:45 PM Bill via groups.io <ko4nrbs=
> [email protected]> wrote:
>
>> Be worth obtaining an adjustable power supply if you plan on doing many
>> board repairs. Why risk damaging boards?
>>
>> Bill
>>
>>
>>
>>
>>
>>
>
>
>
>
>

If you have the possibility pls check the 5V1 at the collector from Q70, mine
is 4,75V. For TTL logic (U670, 671, 673 & 675) this is the absolute minimum.
Maybe this is the reason of the problem so I am interested in the value from
your PG506.

And also look that if inside your PG506 T130 in the power supply is about
70°C when the STD AMP switch is activated. So almost not possible to you put
your finger on the windings of it. Is this on yours the same?
Thanks so far and hopefully you have some suggestions, Rene

They can be pretty rugged. I bought a RM502 years ago and when it
arrived there was almost no packing material in the box, and one corner of
the front panel had breached the cardboard a little and was bent (not
badly, but based on the listing photos, it was new damage). After hearing
so many tragic stories, I feared the worst, but the CRT was fine, and it
worked great.
-Dave
On Sunday, May 2, 2021, 09:07:11 AM PDT, ChuckA <chuck@...>
wrote:

I've been reading this thread and am wondering what 500 scope are you
moving and how far?

I've moved many of them in the back of my truck just wrapped in a moving
blanket and secured so they can't slide around with no problems. This
includes three 555's, shortest trip was about 40 miles the longest was
400 miles. I never opened them up when picked up, just wrap them up.
I've either been really lucky or they are much more rugged then most
people realize.

I do follow common sense, don't throw them in the truck and don't drop
them.

Chuck



On 5/2/2021 11:23 AM, Leon Robinson wrote:

Jeff

Take a screwdriver to remove the cover & a handfull of 8 or 11 inch

tyraps just in case there is something wrong you can then secure it.

Leon Robinson K5JLR

-------- Original message --------
From: Jeff Dutky <jeff.dutky@...>
Date: 05/01/2021 7:19 PM (GMT-06:00)
To: [email protected]
Subject: Re: [TekScopes] Transporting a 500-Series Scope without

Breaking the CRT

Paul,

I used to haul large CRTs (21" computer displays) this way, which are

admittedly less finicky than an old tek scope, at least they never seemed
to care about orientation, and I would seatbelt them in. They were all deep
enough that the seatbelt was near its limit, so they were held in pretty
securely that way. For this, however, I will try to pick up some bungie
cords or something, to get a good strap around the seat back. I was going
to bring some larger blocks of closed cell foam to give it some cushioning
in case I had to put it in back, but I can use the same foam to wedge
against the dash in front.

I'm still a little worried about the CRT mounting in the case. I can't

seem to find the thread now (and maybe it wasn't in this group; maybe it
was in a Facebook group I also belong to) where someone had moved a
500-series scope but some part of the CRT mounting hardware had failed and
the neck had shattered. I'd really like to avoid that sort of tragedy if at
all possible.

-- Jeff Dutky

--
See Early TV at:

www.myvintagetv.com

Jeff

Take a screwdriver to remove the cover & a handfull of 8 or 11 inch tyraps just in case there is something wrong you can then secure it.


Leon Robinson ?K5JLR

-------- Original message --------
From: Jeff Dutky <jeff.dutky@...>
Date: 05/01/2021? 7:19 PM? (GMT-06:00)
To: [email protected]
Subject: Re: [TekScopes] Transporting a 500-Series Scope without Breaking the CRT
?
Paul,

I used to haul large CRTs (21" computer displays) this way, which are admittedly less finicky than an old tek scope, at least they never seemed to care about orientation, and I would seatbelt them in. They were all deep enough that the seatbelt was near its limit, so they were held in pretty securely that way. For this, however, I will try to pick up some bungie cords or something, to get a good strap around the seat back. I was going to bring some larger blocks of closed cell foam to give it some cushioning in case I had to put it in back, but I can use the same foam to wedge against the dash in front.

I'm still a little worried about the CRT mounting in the case. I can't seem to find the thread now (and maybe it wasn't in this group; maybe it was in a Facebook group I also belong to) where someone had moved a 500-series scope but some part of the CRT mounting hardware had failed and the neck had shattered. I'd really like to avoid that sort of tragedy if at all possible.

-- Jeff Dutky

Jeff

Take a screwdriver to remove the cover & a handfull of 8 or 11 inch tyraps just in case there is something wrong you can then secure it.


Leon Robinson ?K5JLR

-------- Original message --------
From: Jeff Dutky <jeff.dutky@...>
Date: 05/01/2021 7:19 PM (GMT-06:00)
To: [email protected]
Subject: Re: [TekScopes] Transporting a 500-Series Scope without Breaking the CRT
Paul,

I used to haul large CRTs (21" computer displays) this way, which are admittedly less finicky than an old tek scope, at least they never seemed to care about orientation, and I would seatbelt them in. They were all deep enough that the seatbelt was near its limit, so they were held in pretty securely that way. For this, however, I will try to pick up some bungie cords or something, to get a good strap around the seat back. I was going to bring some larger blocks of closed cell foam to give it some cushioning in case I had to put it in back, but I can use the same foam to wedge against the dash in front.

I'm still a little worried about the CRT mounting in the case. I can't seem to find the thread now (and maybe it wasn't in this group; maybe it was in a Facebook group I also belong to) where someone had moved a 500-series scope but some part of the CRT mounting hardware had failed and the neck had shattered. I'd really like to avoid that sort of tragedy if at all possible.

-- Jeff Dutky

What would you consider good power supplies given what you've said?

Harvey


On 5/1/2021 9:37 PM, - wrote:

"Be worth obtaining an adjustable power supply if you plan on doing many
board repairs. Why risk damaging boards?"

Absolutely! And use a PS with an adjustable current limit and set the
limit only slightly higher than the amount of current that you expect the
item under test to draw. I used to keep notebooks full of notes about
various repairs including how much power that model item actually drew
under various operating conditions. I also STRONGLY suggest using a GOOD
quality PS like those from HP, Lambda, etc and not one of cheap Chinese
ones. Many of the cheap PSs contain large filter caps on their output in
oder to reduce AC ripple but those large caps can provide enough power to
fry your electronics before their *slow* current limiters can kick in.
GOOD PSs are expensive when new but used ones are available just about
anywhere (at least in the US and Canada) and are usually very cheap

(~$20)

On Sat, May 1, 2021 at 8:45 PM Bill via groups.io <ko4nrbs=
[email protected]> wrote:

Be worth obtaining an adjustable power supply if you plan on doing many
board repairs. Why risk damaging boards?

Bill