Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

Thread Closed
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Tuning on Philco 46-200, 48-200
#10

I Thank you for the suggestion, I have it better but not perfect.
I am not an expert, I don't understand the terminology being put forward. I am coming from a background of computer science and working on old phones, which is vastly simpler that radios.

I have no electronics background, but have a healthy respect for electricity and alway try to be safe (Isolation Transformer, Variaac etc)

Some of the suggestions here, I simply don't understand what exactly you are suggestion. Perhaps that means I should be doing this type of work, but I really would like to learn more about working on these type of radios, just under a safe enviorment.

For example the following suggestions, I don't even know where to begin with regard to them

As for the bypass capacitors, yes they are usually paper caps, there is a large one that goes between the B- and the chassis, in Philco sets there is also a coil in series with it, if this is left out the set will howl and motorboat. There may also be a few others that run between various things and the B-, B- is what some call common negative.

Also be sure the built-in antanna loop is connected correctly AND that it has continuity. If there is an open loop, AVC voltage will not get to the front end tube and the gain will run wide open also causing the exact distortion you have. Also check all the components in the AVC buss as well as the 150K resistor at the loop.
[AVC is Automatic Volume Control ? I have no idea as to how to check components in the AVC buss and the 150K resistor at the loop. Is there a part of the schematic that shows AVC buss ??? Again, real new to this and the terminalogy, schematics, etc are killing me]

Those loop antennas have fairly thin wires and it isn't unusual for the wire at either end to break off on the secondary winding where it is soldered to the chassis or the antenna section of the tuning condenser. In fact on many of these late 40s Philcos the loop antenna is glued onto the inside perimeter of the cabinet, you really have no choice but to disconnect it to get the chassis out, and there are four wires coming off of it, two go to chassis ground (not B-), one goes to the tuning condenser, and one is the external antenna connection. If this is the case then they would have had to disconnect the loop antenna to remove the chassis in both sets, this my be why both appear to have the same problem.
[Yes, this has the loop glued into the inside of the case, and you do have to unsolder to get the chassis fully out. There are 4 wires coming off of it ???? I only see 2 ]

I'd also test for continuity of the IFT's, both pri and sec windings.
[what is continuity, what are the primary and secondary windings ?]


I really appreciate the help, I am trying to look up as much terminology as possible, but I am lost as to what some of these things are that you want me to check.


Messages In This Thread
Tuning on Philco 46-200, 48-200 - by winkydink - 10-23-2012, 09:55 PM
RE: Tuning on Philco 46-200, 48-200 - by Arran - 10-24-2012, 07:19 PM
RE: Tuning on Philco 46-200, 48-200 - by Arran - 10-25-2012, 01:45 AM
RE: Tuning on Philco 46-200, 48-200 - by Arran - 10-25-2012, 05:12 PM
RE: Tuning on Philco 46-200, 48-200 - by winkydink - 10-28-2012, 10:53 AM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Model 70 Cabinet Trim
Although I have not made any cabinets or cabinet parts for a couple of years, I still have some parts left over, includi...Steve Davis — 06:26 PM
philcorepairbench.com - shadow-meter
Thanks Ron.fenbach — 02:43 PM
Model 70 Cabinet Trim
Thank you, Gary. Before making my original post, I had clicked on "Steve Davis Cabinets" only to find that it...musar — 02:25 PM
philco predicta
Welcome to the Phorum, cgl18! I am not your resource for television repair, but lots of friendly help is available here...GarySP — 02:12 PM
Model 70 Cabinet Trim
Welcome to the Phorum, musar! You can send Steve Davis a private message (PM). The site is at the top of the Home page...GarySP — 02:09 PM
Model 70 Cabinet Trim
How do I contact him? The only contact information for him I could find when searching online was a telephone number th...musar — 10:38 AM
philco predicta
Hello, good afternoon, I would like to ask what the possible problem could be if I don't have an image on the screen. I ...cgl18 — 10:19 AM
Philco model 38 code 121 not receiving signal.
So one last question before I finish this radio. Regarding the speaker and output transformer. I salvaged the original o...Stormlord5500 — 09:31 AM
462ron
It’s on the bottom of the homepage of our Philcoradio.com homepage! Ron462ron — 07:20 AM
Model 70 Cabinet Trim
Steve might have some trim left. Not sure he is making anything.morzh — 06:12 AM

[-]
Who's Online
There are currently 513 online users. [Complete List]
» 1 Member(s) | 512 Guest(s)
Avatar

>