I’ve seen this issue for Inova consoles come from the PTS synthesizer.
The electrolytic capacitors dry up and you get a 60Hz AC bleed through. Replacing
the capacitors fixes the issue.
Dan
> From: main_at_ammrl.groups.io on behalf of brcherry_at_asu.edu
> Date: Tuesday, March 5, 2024 at 1:24 PM
> To: main_at_ammrl.groups.io <main_at_ammrl.groups.io>
> Subject: [AMMRL] Leaking 60 hz A/C voltage #Hardware #Troubleshooting #varian
Our aging Varian MR400 has developed a nasty problem. There seems to be 60 Hz
A/C leaking across the ground. I can detect it on the rack and and any non-painted
metal surface in the console. The MR400 design has the console power supply,
generation of all DC voltage, Shim power supply, and both RF amplifiers in one unit.
With only that unit powered, and no connections to the rest of the console, I can
detect a 100 mVpp 60 hz signal if connected to the INPUT of the rf amplifiers.
Comparing this to another aging VNMRS console, only 5 mV pp A/C is observed. The
issue with our MR400 is bad enough that the amplifiers indicate they are in CW mode
at all times. Visual inspection shows nothing "burnt out".
Has anyone run into this issue? Are there any usual suspects to look at in
hopes of determining what has gone wrong to create this issue?
Thank you,
Brian
-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#1048): https://urldefense.com/v3/__https://ammrl.groups=
.io/g/main/message/1048__;!!PvDODwlR4mBZyAb0!QqLwQebkPAZhFdOkUm-JGOmJRx35ZL=
EC_pCdSQ5y-zNVwy6R1hs2garNo9nQ7bvzyPLOsXLimLe2fXuu$
Mute This Topic: https://urldefense.com/v3/__https://groups.io/mt/104750707=
/7559972__;!!PvDODwlR4mBZyAb0!QqLwQebkPAZhFdOkUm-JGOmJRx35ZLEC_pCdSQ5y-zNVw=
y6R1hs2garNo9nQ7bvzyPLOsXLimJ4hFaYt$
Mute #hardware:
https://urldefense.com/v3/__https://ammrl.groups.io/g/main/m=
utehashtag/hardware__;!!PvDODwlR4mBZyAb0!QqLwQebkPAZhFdOkUm-JGOmJRx35ZLEC_p=
CdSQ5y-zNVwy6R1hs2garNo9nQ7bvzyPLOsXLimFvF9HW7$
Mute #troubleshooting:
https://urldefense.com/v3/__https://ammrl.groups.io/g=
/main/mutehashtag/troubleshooting__;!!PvDODwlR4mBZyAb0!QqLwQebkPAZhFdOkUm-J=
GOmJRx35ZLEC_pCdSQ5y-zNVwy6R1hs2garNo9nQ7bvzyPLOsXLimPNIr9LP$
Mute #varian:
https://urldefense.com/v3/__https://ammrl.groups.io/g/main/mut=
ehashtag/varian__;!!PvDODwlR4mBZyAb0!QqLwQebkPAZhFdOkUm-JGOmJRx35ZLEC_pCdSQ=
5y-zNVwy6R1hs2garNo9nQ7bvzyPLOsXLimBW7kOYg$
Group Owner: main+owner_at_ammrl.groups.io
-=-=-=-=-=-=-=-=-=-=-=-
Received on Tue Mar 05 2024 - 10:57:19 MST