Seeking Regency ACT-T16K OR ACT-T720 SCANNER MIXER BOARD SCHEMATIC

[Bob2UfromMe]

Hello All-

I have a Regency ACT-T16K AND AFTER OVER 30 YEARS IN MY GARAGE I TURN IT ON. The LED's worked and I got a momentary squelch pop at turn on... and then that was it... no sound. No volume or squelch adjustment working opened up the unit and found a non-connected blue shielded wire with what appears to be a black stripe running the length of the wire on the VCO BOARD THAT WAS NOT CONNECTED. Found the connection point (by a huge 10-watt resistor) and remade the connection and "Wala". Squelch and Volume now work and sound fine. I can adjust both now and I found the programming instructions, and all appears to be programmed, but no 162.550 NOAA weather or any other local frequencies that I programmed in the unit work. A closer view of the Mixer board which is the smallest board mounted by the VCO board has what appears to be an almost clear sealant covering two transistors and a tuning coil and a couple of capacitors. All the transistors have the case of the TO-92 case shape, which is the shape most people think of when thinking of a transistor. I could see two of the transistors on the board and they appear to be Motorola, but I can't find any information on their identification on the web. One transistor was labeled "M11-020 and below that is 719" and after my 30 years of working in electronics I have never found or seen any Motorola number identifications like this. The other transistor was marked "M11-025 and below that was 636". I have no idea on what this transistor is either. There are transistors without any identification, but have a "red top color" on the VCO BOARD??? Without a schematic I assume that is the problem transistor! If someone out there in radio land could give me some info I would appreciate it. Also, the M11-020 719 transistor has overheated and melted the solid glue that was over that section of the circuit board as can be seen in the following link. Go to the Third photo from top of the page and is the top view of the scanner with a description above on the link...
"Top view of the opened Regency Radio Scanner ACT-T16K with three printed circuit boards (PCBs) visible.
Left: Receiver-PCB, upper right: VCO-PCB and lower right: Mixer-PCB."

See the photo at http://www.datamath.org/TI_Stuff/JPEG_Regency_ACT-T16K.htm#:~:text=Bottom%20view%20of%20the%20opened%20Regency%20Radio

I appreciate any assistance you can give.
Sincerely,
Bob2ufromMe

 

[pro92b]

Unless the case of a component is cracked open it is not reliable to try finding bad parts by visual inspection. Transistors can be checked by using a digital multimeter on the diode test scale to check the base-emitter and base-collector junctions for proper conduction.

The red top transistors are 2N5222 as listed in the TME-8H service manual here: Parts List - Regency TME-8H Service Manual [Page 30]

The 2N5222 red top transistors may be selected for some parameter like beta but that information is not available.

The author of the datamath site said he has a service manual. His email is at the bottom of the page you linked and maybe he can send you a copy.

Regency ACT-T16K is a post by a forum member who has a service manual. He has not been active lately but you could try contacting him.

MANUALMAN.COM: Manualman Online is a listing for the service manual for sale at $15.

If you do find a service manual, please make it available to forum members.

 

[pro92b]

Here is an update to my previous post. The service manual for the ACT-W10 available at mods.dk -> Instruction, users and service manuals for Regency lists the -020 (2N5245) and -025 (2N5953) transistors on page 33. These are FET types so the diode junction test I referenced before will not work because that is for bipolar transistors.

The numbering on the transistors and IC's is Regency's house numbering. This was common with some manufacturers where they had semiconductors from major suppliers like Motorola marked with their own house numbers. Sometimes these parts had specially selected parameters but were often just re-marked standard parts.

 

[Bob2UfromMe]

Here is an update to my previous post. The service manual for the ACT-W10 available at mods.dk -> Instruction, users and service manuals for Regency lists the -020 (2N5245) and -025 (2N5953) transistors on page 33. These are FET types so the diode junction test I referenced before will not work because that is for bipolar transistors.

The numbering on the transistors and IC's is Regency's house numbering. This was common with some manufacturers where they had semiconductors from major suppliers like Motorola marked with their own house numbers. Sometimes these parts had specially selected parameters but were often just re-marked standard parts.

Thank you so much! I am so grateful for your assistance! I had almost given up looking for those transistors.

 

[Bob2UfromMe]

Here is an update to my previous post. The service manual for the ACT-W10 available at mods.dk -> Instruction, users and service manuals for Regency lists the -020 (2N5245) and -025 (2N5953) transistors on page 33. These are FET types so the diode junction test I referenced before will not work because that is for bipolar transistors.

The numbering on the transistors and IC's is Regency's house numbering. This was common with some manufacturers where they had semiconductors from major suppliers like Motorola marked with their own house numbers. Sometimes these parts had specially selected parameters but were often just re-marked standard parts.

Thank you, so much many times over! I scoured the internet from here to China and Russia...literally and found nothing.