Posts: 194
Threads: 34
Joined: Jul 2016
City: Spring Lake MI
PT-26, having an unusual problem at least for me it is. I have the chassis restored plays great outside the cabinet. When it is placed it in the cabinet the reception goes crazy it gets completely distorted, remove the chassis from the cabinet it fine. This radio has the loop antenna in the middle of the cabinet it looks good as soon as i get the chassis halfway in it goes nuts. I tried to duplicate the problem outside the cabinet but could not. I am assuming the the radio is causing interference with the loop antenna.
Your thoughts
Jim
Spring Lake MI
Posts: 4,383
Threads: 412
Joined: Jun 2011
City: Boston
State, Province, Country: Massachusetts
Connection to loop OK, something getting crossed over each other when putting in case?
Odd one.
Paul
Tubetalk1
Posts: 7
Threads: 1
Joined: Dec 2018
City: WOODSTOCK
State, Province, Country: Virginia
Unusual to have the loop halfway inside the cabinet -- is that factory? Can you move it to the back? Can you place the loop outside the cabinet to see the effect? My guess is the loop is interacting with the converter or the IF amp - loktal tubes - see if a shield over one or both those tubes does any good.......Verify all component grounds are solid. Are the loop antenna leads correctly connected? Good luck.
Posts: 194
Threads: 34
Joined: Jul 2016
City: Spring Lake MI
Yes Steve the loop is factory and is glued in place. I shall do some checking on the grounds. I found today that the interference starts when the chassis is only partially in. The leads from the loop are connected where it show on the schematic.
Thanks
Jim
Spring Lake MI
Posts: 4,383
Threads: 412
Joined: Jun 2011
City: Boston
State, Province, Country: Massachusetts
Is the loop one of the style that is wound strands of wiring glued around the perimeter in side case, normally the were place at the outside edge of case, the chassis would slip in beyond it and then solder lead to antenna connection.
Maybe somebody has tinkered....?
Paul
Tubetalk1
Posts: 194
Threads: 34
Joined: Jul 2016
City: Spring Lake MI
Thanks guys, what I found, under the chassis is the 2nd IF can non-adjustable, it felt loose so I tightened it really good from on top and that solved the problem. I have been playing it and so for preforming very well.
So thanks for your input, I think Steve nail it the can was not grounded thoroughly.
Jim
Spring Lake MI