Any ideas appreciated. I just recapped a Model 80 I picked up a while ago. I went through the tuning procedures OK, but reception is really poor. I barely get 1 local station that usually comes in wall-to-wall. If I clip the antenna directly to the grid cap of the 1st stage, reception is improved with better volume and a few more stronger stations. Alignment only needed low-level generator signal, so nothing seemed odd when I went through the procedures. Biasing on 1st #36 looks not too bad, 250 plate, 95 screen grid. Inject signal at 2nd stage, comes through loud and clear. I'm suspecting the antenna coil as I've read these early Philco's can have problems in that area, but get primary and secondary continuity (2 ohms and 7 ohms). Tough to read my Riders copy, but I think those are OK readings. Volume control checks out and I swapped it out just to be sure. Saw the performance notes at phiclorepairbench but before I tried those mods, wanted to be sure I'm not missing something else.

If touching the grid cap of the 1st stage improves reception, it means that something is open in the antenna circuit. Check that area for continuity.
Doug

:If touching the grid cap of the 1st stage improves reception, it means that something is open in the antenna circuit. Check that area for continuity.
:Doug

Thanks. Checked grid cap to chassis. Antenna to chassis through the volume control, full on through full off positions. Double checked. Continuity on all paths. Definite improvement with antenna going to grid cap versus transformer input. I'm thinking something is up with the transformer, but not finding an open has me second guessing.

You have to check everything in the antenna ckt for continuity, including the primary and secondary windings of the antenna xfmr. Use the schematic to figure out where to place your ohmmeter probes: http://www.nostalgiaair.org/PagesByModel/843/M0013843.pdf

Everytime I've encountered your symptoms, there was something open in the antenna ckt.
Doug

:
:Thanks. Checked grid cap to chassis. Antenna to chassis through the volume control, full on through full off positions. Double checked. Continuity on all paths. Definite improvement with antenna going to grid cap versus transformer input. I'm thinking something is up with the transformer, but not finding an open has me second guessing.

EVEN THOUGH UR COIL HAS CONTINUITY DOESNT MEAN ITS GOOD. YOU COULD HAVE ADJACENT TURNS SHORTED TO EACH OTHER EFFECTIVELY LOSING TURNS AND INDUCTANCE. UNVERSAL COILS CAN BE BOUGHT CHEAP AT ANTIQUE ELECTRIC SUPPLY AS SOMETHING TO TRY
:You have to check everything in the antenna ckt for continuity, including the primary and secondary windings of the antenna xfmr. Use the schematic to figure out where to place your ohmmeter probes: http://www.nostalgiaair.org/PagesByModel/843/M0013843.pdf
:
:Everytime I've encountered your symptoms, there was something open in the antenna ckt.
:Doug
:
::
::Thanks. Checked grid cap to chassis. Antenna to chassis through the volume control, full on through full off positions. Double checked. Continuity on all paths. Definite improvement with antenna going to grid cap versus transformer input. I'm thinking something is up with the transformer, but not finding an open has me second guessing.

It sounds like the antenna coil has shorted windings. here is a good link on how to repair the coil.

http://www.oldradiosrus.com/build.html

Hi, you might want to check your resistors, I had one that did basically the same thing although it was a newer model. Everything pointed to the antenna circut but it was a bad resistor. I think it was called a grid leak resistor. I would touch the grid cap and reception would improve. Good Luck.

Checking resistors is always a good idea. But this set doesn't have a grid leak resistor: http://www.nostalgiaair.org/PagesByModel/843/M0013843.pdf
Doug

:Hi, you might want to check your resistors, I had one that did basically the same thing although it was a newer model. Everything pointed to the antenna circut but it was a bad resistor. I think it was called a grid leak resistor. I would touch the grid cap and reception would improve. Good Luck.

:Thanks for the info Doug, I have sooooo much more to learn. George T
:
:Checking resistors is always a good idea. But this set doesn't have a grid leak resistor: http://www.nostalgiaair.org/PagesByModel/843/M0013843.pdf
:Doug
:
::Hi, you might want to check your resistors, I had one that did basically the same thing although it was a newer model. Everything pointed to the antenna circut but it was a bad resistor. I think it was called a grid leak resistor. I would touch the grid cap and reception would improve. Good Luck.

Thanks again to all for your input. General concensus seems to point to the transformer, which I suspect is the problem even though it doesn't read open in either primary or secondary. At these low resistances, shorted turns would be near impossible to determine. I've heard that some of these coils can be rewound, so maybe I'll give that a try next week.

:It sounds like the antenna coil has shorted windings. here is a good link on how to repair the coil.
:
:
:http://www.oldradiosrus.com/build.html

John,

Before condeming the antenna transformer, I would verify that the ground on each winding is good to the chassis/B-.

Radiodoc
******************

:Thanks again to all for your input. General concensus seems to point to the transformer, which I suspect is the problem even though it doesn't read open in either primary or secondary. At these low resistances, shorted turns would be near impossible to determine. I've heard that some of these coils can be rewound, so maybe I'll give that a try next week.
:
::It sounds like the antenna coil has shorted windings. here is a good link on how to repair the coil.
::
::
::http://www.oldradiosrus.com/build.html

Good point. Continuity at coil to ground connections seem to be OK. Measured antenna and grid cap to volume control ground terminal, then volume control ground terminal to several points on the chassis. All seem to check out. It's a simple circuit with not much to really go wrong but whatever it is, isn't easily seen or measured.

:John,
:
:Before condeming the antenna transformer, I would verify that the ground on each winding is good to the chassis/B-.
:
:Radiodoc
:******************
:
:
:
::Thanks again to all for your input. General concensus seems to point to the transformer, which I suspect is the problem even though it doesn't read open in either primary or secondary. At these low resistances, shorted turns would be near impossible to determine. I've heard that some of these coils can be rewound, so maybe I'll give that a try next week.
::
:::It sounds like the antenna coil has shorted windings. here is a good link on how to repair the coil.
:::
:::
:::http://www.oldradiosrus.com/build.html

:Any ideas appreciated. I just recapped a Model 80 I picked up a while ago. I went through the tuning procedures OK, but reception is really poor. I barely get 1 local station that usually comes in wall-to-wall. If I clip the antenna directly to the grid cap of the 1st stage, reception is improved with better volume and a few more stronger stations. Alignment only needed low-level generator signal, so nothing seemed odd when I went through the procedures. Biasing on 1st #36 looks not too bad, 250 plate, 95 screen grid. Inject signal at 2nd stage, comes through loud and clear. I'm suspecting the antenna coil as I've read these early Philco's can have problems in that area, but get primary and secondary continuity (2 ohms and 7 ohms). Tough to read my Riders copy, but I think those are OK readings. Volume control checks out and I swapped it out just to be sure. Saw the performance notes at phiclorepairbench but before I tried those mods, wanted to be sure I'm not missing something else.

Actually, I've tried several and it didn't help.

::Any ideas appreciated. I just recapped a Model 80 I picked up a while ago. I went through the tuning procedures OK, but reception is really poor. I barely get 1 local station that usually comes in wall-to-wall. If I clip the antenna directly to the grid cap of the 1st stage, reception is improved with better volume and a few more stronger stations. Alignment only needed low-level generator signal, so nothing seemed odd when I went through the procedures. Biasing on 1st #36 looks not too bad, 250 plate, 95 screen grid. Inject signal at 2nd stage, comes through loud and clear. I'm suspecting the antenna coil as I've read these early Philco's can have problems in that area, but get primary and secondary continuity (2 ohms and 7 ohms). Tough to read my Riders copy, but I think those are OK readings. Volume control checks out and I swapped it out just to be sure. Saw the performance notes at phiclorepairbench but before I tried those mods, wanted to be sure I'm not missing something else.

Give you 30 bucks for the radio :)

:Actually, I've tried several and it didn't help.
:
:
:::Any ideas appreciated. I just recapped a Model 80 I picked up a while ago. I went through the tuning procedures OK, but reception is really poor. I barely get 1 local station that usually comes in wall-to-wall. If I clip the antenna directly to the grid cap of the 1st stage, reception is improved with better volume and a few more stronger stations. Alignment only needed low-level generator signal, so nothing seemed odd when I went through the procedures. Biasing on 1st #36 looks not too bad, 250 plate, 95 screen grid. Inject signal at 2nd stage, comes through loud and clear. I'm suspecting the antenna coil as I've read these early Philco's can have problems in that area, but get primary and secondary continuity (2 ohms and 7 ohms). Tough to read my Riders copy, but I think those are OK readings. Volume control checks out and I swapped it out just to be sure. Saw the performance notes at phiclorepairbench but before I tried those mods, wanted to be sure I'm not missing something else.

What's the correct antenna to use on this model radio?

I'm still working on this one, and have come to the conclusion that the radio electronics are working OK. If I use my RF generator at the antenna (through a capacitor), very low level signal in gets loud signal out. I can see the RF signal increase through the antenna transformer (that I suspected to be a problem, so I rewound the primary)looking at the input and output with my scope. Still, my wire antenna (about 8' long) gets hardly anything but connect it to the first 36 grid cap, and the signal is stronger. While checking it out, the end of my antenna wire came in contact with my metal parts shelf and the station I was tuned to came in loud and clear. Also received many other stonger and weaker stations. I've come to the conclusion that I need to try a better antenna but what kind and how long must a long wire be, if that's what this radio needs?

::Any ideas appreciated. I just recapped a Model 80 I picked up a while ago. I went through the tuning procedures OK, but reception is really poor. I barely get 1 local station that usually comes in wall-to-wall. If I clip the antenna directly to the grid cap of the 1st stage, reception is improved with better volume and a few more stronger stations. Alignment only needed low-level generator signal, so nothing seemed odd when I went through the procedures. Biasing on 1st #36 looks not too bad, 250 plate, 95 screen grid. Inject signal at 2nd stage, comes through loud and clear. I'm suspecting the antenna coil as I've read these early Philco's can have problems in that area, but get primary and secondary continuity (2 ohms and 7 ohms). Tough to read my Riders copy, but I think those are OK readings. Volume control checks out and I swapped it out just to be sure. Saw the performance notes at phiclorepairbench but before I tried those mods, wanted to be sure I'm not missing something else.

The longer the wire, the more signal it catches. Use at least 15 to 25 feet. best if it's outside too.

I'll put money on the coils.

:Any ideas appreciated. I just recapped a Model 80 I picked up a while ago. I went through the tuning procedures OK, but reception is really poor. I barely get 1 local station that usually comes in wall-to-wall. If I clip the antenna directly to the grid cap of the 1st stage, reception is improved with better volume and a few more stronger stations. Alignment only needed low-level generator signal, so nothing seemed odd when I went through the procedures. Biasing on 1st #36 looks not too bad, 250 plate, 95 screen grid. Inject signal at 2nd stage, comes through loud and clear. I'm suspecting the antenna coil as I've read these early Philco's can have problems in that area, but get primary and secondary continuity (2 ohms and 7 ohms). Tough to read my Riders copy, but I think those are OK readings. Volume control checks out and I swapped it out just to be sure. Saw the performance notes at phiclorepairbench but before I tried those mods, wanted to be sure I'm not missing something else.

How are your voltage readings?

:I'll put money on the coils.
:
::Any ideas appreciated. I just recapped a Model 80 I picked up a while ago. I went through the tuning procedures OK, but reception is really poor. I barely get 1 local station that usually comes in wall-to-wall. If I clip the antenna directly to the grid cap of the 1st stage, reception is improved with better volume and a few more stronger stations. Alignment only needed low-level generator signal, so nothing seemed odd when I went through the procedures. Biasing on 1st #36 looks not too bad, 250 plate, 95 screen grid. Inject signal at 2nd stage, comes through loud and clear. I'm suspecting the antenna coil as I've read these early Philco's can have problems in that area, but get primary and secondary continuity (2 ohms and 7 ohms). Tough to read my Riders copy, but I think those are OK readings. Volume control checks out and I swapped it out just to be sure. Saw the performance notes at phiclorepairbench but before I tried those mods, wanted to be sure I'm not missing something else.
: