UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Bush VHF61

David G4EBT · 10th Aug 2022, 9:35 pm

Apart from the low voltage on pin 7 when on VHF, when you state that Pin 1 (grid) when tuned to a station on VHF = -0.5mv and on MW = -2.2v, that confirms that for whatever reason, there is virtually no negative voltage swing when a station is tuned in on VHF. You will only see a display on VHF similar to that when a station is tuned in on MW if you have a similar level of negative voltage on the EM81 grid.

Attached below is a clip from the (ERT) data regarding the operation of the magic eye on both AM and FM.

10th Aug 2022, 9:35 pm	#14
David G4EBT Dekatron Join Date: Feb 2003 Location: Cottingham, East Yorkshire, UK. Posts: 5,763	Re: Bush VHF61 - magic eye not closing. Apart from the low voltage on pin 7 when on VHF, when you state that Pin 1 (grid) when tuned to a station on VHF = -0.5mv and on MW = -2.2v, that confirms that for whatever reason, there is virtually no negative voltage swing when a station is tuned in on VHF. You will only see a display on VHF similar to that when a station is tuned in on MW if you have a similar level of negative voltage on the EM81 grid. Attached below is a clip from the (ERT) data regarding the operation of the magic eye on both AM and FM. Attached Thumbnails __________________ David. BVWS Member. G-QRP Club member 1339.