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7704 power supply

Tom Jobe
 

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Hi Tom,
It is not clear who you are talking to with your 3D drawing request, but my offer is limited to a simple dimensioned sketch of my simplified 4xx feet only.
Mike asked whether the material was Delrin, yes it is.
Delrin is easy to get on eBay and elsewhere, and it machines very nicely.
Obviously one could use whatever material?they had on hand, metal, plastic or whatever.
If you didn't care about being able to wrap the power cord around the feet, some very simple round feet with a screw hole?down the middle would do nicely. Imagine some pieces of plastic bar stock cut off to the length you wanted, with a counter bored hole so the screw heads wouldn't?damage the floor when the scope was stood on end.
tom jobe...
?
?
?
?

----- Original Message -----
From: Tom Miller
Sent: Wednesday, May 23, 2012 6:08 AM
Subject: Re: [TekScopes] Re: 7704 power supply

?

Can you produce a 3D drawing that one could put out for bids for an injection molded part? How many different scopes were these feet used on? I wonder if they could be made for say $20 a set? I have bought new old stock in the original Tek package and they fall apart out of the bag. I also have trimmed a Tek foot down and fit it to the HP 174xA scopes so maybe a common design that could be used on either scope would be good.
?
Regards,
Tom M
?
?
?
----- Original Message -----
From: Tom Jobe
Sent: Tuesday, May 22, 2012 10:01 PM
Subject: Re: [TekScopes] Re: 7704 power supply [4 Attachments]

?

Having been through the 4xx crumbling rear foot problem several times, I made up some replacement feet out of plastic bar stock.
Attached are some pictures of these new feet. The power cord wraps around them just like the originals.
I have no interest in making any of these feet?for anyone, but I will offer to make a simple dimensioned sketch if anyone wants it.
tom jobe...
?
?
?
----- Original Message -----
From: EB4APL
Sent: Tuesday, May 22, 2012 6:33 PM
Subject: Re: [TekScopes] Re: 7704 power supply

?

Hi Raymond,

When I bought my 465 it also had the disintegrating rubber feet.? Since they are also used as cable wrap I wanted to replace them and found a set NOS from a reputable seller.? I bought them but they began to also disintegrate within days.? They were really new, in an original Tek bag, but it seems that the rubber deteriorates with time so probably all the feet that you find, either used or new, will also disintegrate.? Anyway YMMV (Is it the correct spelling?).

Regards,
Ignacio, EB4APL


On 22/05/2012 21:31, raymonddompfrank wrote:

?


Wanting to avoid too long a message, I didn't mention that I "lost" that 465 in 1994 when I sold my company.
However:
In recent weeks I have purchased a 465B in excellent condition, without the rubber feet (disintegrated, anyone knows where to get those?), an R7844 in excellent condition, a mostly non-functional 2445B (since repaired) and ... a 7704A, now repaired!
It turned out that one bridge rectifier diode (CR3182) on the inverter/rectifier board had short-circuited.
I replaced it with a diode (1N5406) from a broken Apple PowerMac G5 computer. I guess it'll do the job OK. The circuit is just supplying 5V for the indicator lights.

Reason I used a DMM is, the maintenance manual states that the pre-regulator +54V should be 54.2 +- 0.25 V. I don't understand why it should be within 0,5% but it's certainly easier to measure with a DMM than with a scope...

Now I only have to correct the brightness/focus isssue...

Raymond
Raymond
--- In TekScopes@..., "Albert" wrote:
>
> Actually you said a 465.
> Albert
>
> > First thing is to throw away your DMM: why do you have a 7844?
>
Albert
 

Hi guys,
Isn't it better to continue that 465-feet discussion in a new thread?
Albert
 

Hi,

Just about any wood could be lathed except maybe balsa. Lot cheaper too.

Jerry Massengale



-----Original Message-----
From: Tom Jobe
To: TekScopes
Sent: Wed, May 23, 2012 8:55 am
Subject: Re: [TekScopes] Re: 7704 power supply

?
Hi Tom,
It is not clear who you are talking to with your 3D drawing request, but my offer is limited to a simple dimensioned sketch of my simplified 4xx feet only.
Mike asked whether the material was Delrin, yes it is.
Delrin is easy to get on eBay and elsewhere, and it machines very nicely.
Obviously one could use whatever material?they had on hand, metal, plastic or whatever.
If you didn't care about being able to wrap the power cord around the feet, some very simple round feet with a screw hole?down the middle would do nicely. Imagine some pieces of plastic bar stock cut off to the length you wanted, with a counter bored hole so the screw heads wouldn't?damage the floor when the scope was stood on end.
tom jobe...
?
?
?
?
----- Original Message -----
From: Tom Miller
Sent: Wednesday, May 23, 2012 6:08 AM
Subject: Re: [TekScopes] Re: 7704 power supply

?
Can you produce a 3D drawing that one could put out for bids for an injection molded part? How many different scopes were these feet used on? I wonder if they could be made for say $20 a set? I have bought new old stock in the original Tek package and they fall apart out of the bag. I also have trimmed a Tek foot down and fit it to the HP 174xA scopes so maybe a common design that could be used on either scope would be good.
?
Regards,
Tom M
?
?
?
----- Original Message -----
From: Tom Jobe
Sent: Tuesday, May 22, 2012 10:01 PM
Subject: Re: [TekScopes] Re: 7704 power supply [4 Attachments]

?
Having been through the 4xx crumbling rear foot problem several times, I made up some replacement feet out of plastic bar stock.
Attached are some pictures of these new feet. The power cord wraps around them just like the originals.
I have no interest in making any of these feet?for anyone, but I will offer to make a simple dimensioned sketch if anyone wants it.
tom jobe...
?
?
?
----- Original Message -----
From: EB4APL
Sent: Tuesday, May 22, 2012 6:33 PM
Subject: Re: [TekScopes] Re: 7704 power supply

?
Hi Raymond,

When I bought my 465 it also had the disintegrating rubber feet.? Since they are also used as cable wrap I wanted to replace them and found a set NOS from a reputable seller.? I bought them but they began to also disintegrate within days.? They were really new, in an original Tek bag, but it seems that the rubber deteriorates with time so probably all the feet that you find, either used or new, will also disintegrate.? Anyway YMMV (Is it the correct spelling?).

Regards,
Ignacio, EB4APL


On 22/05/2012 21:31, raymonddompfrank wrote:
?

Wanting to avoid too long a message, I didn't mention that I "lost" that 465 in 1994 when I sold my company.
However:
In recent weeks I have purchased a 465B in excellent condition, without the rubber feet (disintegrated, anyone knows where to get those?), an R7844 in excellent condition, a mostly non-functional 2445B (since repaired) and ... a 7704A, now repaired!
It turned out that one bridge rectifier diode (CR3182) on the inverter/rectifier board had short-circuited.
I replaced it with a diode (1N5406) from a broken Apple PowerMac G5 computer. I guess it'll do the job OK. The circuit is just supplying 5V for the indicator lights.

Reason I used a DMM is, the maintenance manual states that the pre-regulator +54V should be 54.2 +- 0.25 V. I don't understand why it should be within 0,5% but it's certainly easier to measure with a DMM than with a scope...

Now I only have to correct the brightness/focus isssue...

Raymond
Raymond
--- In TekScopes@..., "Albert" wrote:
>
> Actually you said a 465.
> Albert
>
> > First thing is to throw away your DMM: why do you have a 7844?
>

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