[Test-Equipment] WTD: Help with old scope problem

Mon Oct 11 13:13:13 EDT 2010

Thank you David, I figure out that the problem is the meter, no readings on 
the 5 KV setting with another source. I'll worry about it later.
Joe
----- Original Message ----- 
From: "David" <davidgreenrecycling at yahoo.com>
To: "Discussion of Electronic Test Equipment" 
<test-equipment at mailman.qth.net>
Sent: Sunday, October 10, 2010 7:04 PM
Subject: Re: [Test-Equipment] WTD: Help with old scope problem

Use a Digital Voltmeter with an impedance of 10 meg ohms or higher. David

--- On Sat, 10/9/10, Joseph Orgnero <josepho at shaw.ca> wrote:

From: Joseph Orgnero <josepho at shaw.ca>
Subject: Re: [Test-Equipment] WTD: Help with old scope problem
To: "Discussion of Electronic Test Equipment" 
<test-equipment at mailman.qth.net>
Date: Saturday, October 9, 2010, 11:41 AM

Thank you Ed,
I do have the original manual, so I'm OK that way.
As for the HV, some other messages state that the 260 is not suitable due to
loading, unfortunately, I don't have a VTVM for that purpose.
I'll follow your advice and go over the scope again, hopefully, I shall be
able to narrow down the problem.
I'll keep you posted.
Joe
----- Original Message ----- 
From: <k4pf at juno.com>
To: <test-equipment at mailman.qth.net>
Sent: Friday, October 08, 2010 1:15 PM
Subject: Re: [Test-Equipment] WTD: Help with old scope problem

>
> Hi, Joe
>
> If you don't have a manual, here is a free one on the 'net:
> http://bama.edebris.com/manuals/tek/310a/
> It is in DejaVu format, so you may need an image viewer
> like Irfan View or XnView, both available at download.com.
>
> You should follow the signal from the external horizontal
> input, and see where it disappears. It could be trouble
> with the horizontal selector switch Sw-210 or the horiz
> amplifier tubes V220 v240. Did you remember to switch
> the mode switch to ext horiz input?
>
> You an use a 6.3V line from the LV power supply
> as a source of horiz input signal. V220 and V440 should probably
> be OK, since there is a controlled deflection using the horiz
> position pot. I assume the pot is near center of its rotation
> for normal mid scale display.
>
> The Simpson 260 is excellent to check HV.
> I'm surprised you get no reading with it
> at the -1675V check point, even though
> you see objects on the screen. You can check the 5642 filaments
> in a dark room this evening. You can check the Simpson 5KV scale
> by connecting to the +300V line.
>
> Have you another scope to work on the Tek?
>
> 73,
> Ed Knobloch
>
>
> ---------- Original Message ----------
> From: "Joseph Orgnero" <josepho at shaw.ca>
> To: "Discussion of Electronic Test Equipment"
> <test-equipment at mailman.qth.net>
> Subject: Re: [Test-Equipment] WTD: Help with old scope problem
> Date: Fri, 8 Oct 2010 10:53:03 -0700
>
> Thank you Ed for the advice, re your comments. The -150 V is OK, I don't
> see
> light on the rectifiers but being sosmall is hard to tell, I don't get any
> deflection using the external horizontal input.
> As for the HV measurement, I'm using a Simpson 260 on the 5 KV range. Is
> this the right kind of meter>
> I'll keep investigating.
> 73's
> Joe
> ----- Original Message ----- 
> From: <k4pf at juno.com>
> To: <test-equipment at mailman.qth.net>
> Sent: Thursday, October 07, 2010 1:51 PM
> Subject: Re: [Test-Equipment] WTD: Help with old scope problem
>
>
>>
>>
>> Hi, Joe
>>
>> Is the -150V correct? Filaments lit on all 5642's?
>>
>> Using external horizontal input on rear panel, do you get
>> any horizontal deflection?
>>
>> Do you have another 'scope to work on this Tek 310A scope?
>>
>> You need a very hi Z meter to look at the HV,
>> like a 20K Ohms per volt VOM with a 5KV scale.
>> (100 Meg Ohms resistance on that range)
>>
>> 73,
>> Ed Knobloch
>>
>>
>> "Joseph Orgnero" <josepho at shaw.ca> wrote
>>>For a number of years Ihave been using a Tek 310A on my bench. I like it
>>>on spite of its age and limited BW because of its small size and sharp
>>>trace. Recently,after not have been used for some months, presnted a
>>>number of problems.
>> - There is no horizontal trace, only a spot.
>> - The spot can be moved in both directions (V&H).
>> - The focus control has only limited effect on the spot.
>> - The intensity control has no effect on it.
>> - The tubes related to the horizontal and sweep sections check OK.
>> - There are no broken, burnt or overheated components.
>> - LV voltages are OK but I cannot get a reading on the HV test point
>> (5642
>> rectifiers).
>> - If I apply a signal from the voltage calibrator, the spot splits on
>> two.
>>
>>
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>
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