UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Midland 77-805 Portapak transmit issue

Damo666 · 30th Oct 2019, 10:21 pm

Hi Sirius,

Thank you for checking the situation with yours.

I opened mine again tonight & can confirm that there is a zero ohm short between the chassis & all metal cans on the PCB.

There is also a zero ohm short between the "MICG" connection wire & the chassis.

I've attached an image of where the "MICG" connection is on the track side of the PCB - pointed at with the meter probe & on a clearer image with a red x.

With regards the blip with the RF power Transistor yesterday, I don't think I put my point across properly so you might have misunderstood me; In a nutshell, what I did was literally connect the TX pin of the Mic' socket directly to the screw holding the Transistor down, essentially connecting C177 & R179 directly to it. It wasn't transmitting.

30th Oct 2019, 10:21 pm	#26
Damo666 Hexode Join Date: Jan 2010 Location: Blackburn, Lancashire, UK. Posts: 399	Re: Midland 77-805 Portapak transmit issue Hi Sirius, Thank you for checking the situation with yours. I opened mine again tonight & can confirm that there is a zero ohm short between the chassis & all metal cans on the PCB. There is also a zero ohm short between the "MICG" connection wire & the chassis. I've attached an image of where the "MICG" connection is on the track side of the PCB - pointed at with the meter probe & on a clearer image with a red x. With regards the blip with the RF power Transistor yesterday, I don't think I put my point across properly so you might have misunderstood me; In a nutshell, what I did was literally connect the TX pin of the Mic' socket directly to the screw holding the Transistor down, essentially connecting C177 & R179 directly to it. It wasn't transmitting. Attached Thumbnails Last edited by Damo666; 30th Oct 2019 at 10:49 pm.