Hi Michael,
Something I forgot to mention that you may not know is that for the power
supplies in a 535 to work, it MUST have a plugin installed, otherwise, the
load on the power supplies will be too light and they will not regulate.
Stan
toggle quoted message
Show quoted text
-----Original Message-----
From: Michael Petereit [mailto:Michael.Petereit@...]
Sent: Tuesday, February 06, 2007 9:10 AM
To: TekScopes; Stan and Patricia Griffiths
Subject: Re: [TekScopes] Re: old fashioned 535 - first start after 35 years
Stan,
I checked the voltages:
+100V = 124V
+225V = 203V
+350V = 306V
+500V = 464V
-150V = -144V
A lot voltage is below the limits. The main supply is switched to 234V,
the current standard voltage is 235V on the power line.
I assume the rectifier might be broken. Since the hartley oscillator is
powered by the +350V line and coupled with the +340V line according
schematics the tube might not run as expected. The frequency must be
aroung 50kHz but I do not have a AM receiver to check ans again the dirt
inside the scope is expecially around the HV and this oscillator horrible.
Any other ideas about the lower voltages ?
BR,
Michael
Stan and Patricia Griffiths said the following on 05.02.2007 22:02:
Hi Michael,
If the relay is opening again after closing, it is not getting coil
voltage from its own contacts. If you burnish (clean) the relay
contacts, it will probably hold in until the power switch is turned off.
It is not usually necessary to check the +8650 volts on the CRT
anode. If the -1350 is present, then the +8650 will be OK. All of
the other power supplies must be working properly before you bother to
measure the -1350. The other supplies are: -150, +100, +225, +350,
and +500.
Stan
------------------------------------------------------------------------
*From:* TekScopes@... [mailto:TekScopes@...]
*On Behalf Of *Michael Petereit
*Sent:* Monday, February 05, 2007 8:19 AM
*To:* m38a1_1962
*Cc:* TekScopes@...
*Subject:* Re: [TekScopes] Re: old fashioned 535 - first start after
35 years
I tried again. Since the CRT is completely covered I cannot see any
filament working.
Shortly before the tube's diameter gets wider some connectors for
deflection I guess. Even there some color avoid having a look onto any
filament.
Is it really colour or might it be dirt ?
The tube is such long you can't have a look from the back unless you
remove the backcover. But I would like to avoid as much disassembling as
possible unless it worked once. Then any other cleaning will happen and
I try to "renovate" the item.
I'll try to get a high voltage adapter for my Gossen multimeter. Then
I'll check the -1350V and the 8960V.
br,
Michael
m38a1_1962 said the following on 05.02.2007 03:35:
Before you go too far with the chassis cleaning and wholesale tube
testing, check and repair the low voltage power supplies first (be
especially wary of the bypass capacitors across the precision voltage
divider resistors). If the voltages are all in tolerance, look at the
high voltage rectifier tubes under the top HV cover to see if their
filaments are glowing. This will tell you if the HV oscillator is
working. If they are glowing, the CRT filament should also be glowing.
You won't be able to fix anything else until the power supplies are
working. BAMA has a 535_545 manual listed for free download if you are
in for some troubleshooting. Good luck.
--- In TekScopes@... <mailto:TekScopes%40yahoogroups.com>
<mailto:TekScopes%40yahoogroups.com>,
Artek Media <manuals@...> wrote:
__________ NOD32 2040 (20070206) Information __________
This message was checked by NOD32 antivirus system.
