[Ron Ramirez]

Yes, that is perfectly fine.

[markmokris]

Ok I am getting a little worried. I unraveled the tickler winding.  I counted 26 turns which is in line with what I have been reading.

   

Underneath, the celluoid insulator (with the little tabs) remains.  It is stuck on there good!  I don't see any possibility of removing it without destroying the winding underneath.

Can I just leave it?

Can I wrap it with a piece of tape, then wrap the new winding on top where the old one was?

Mark

[markmokris]

Ok I am getting a little worried. I unraveled the tickler winding.  I counted 26 turns which is in line with what I have been reading.



Underneath, the celluoid insulator (with the little tabs) remains.  It is stuck on there good!  I don't see any possibility of removing it without destroying the winding underneath.

Can I just leave it?

Can I wrap it with a piece of tape, then wrap the new winding on top where the old one was?

Mark

As Rosanne Rosannadanna would say "Never mind."

I used a little heat and eventually the celluloid strip cracked and broke off mainly in one piece.  The primary and secondary seem to remain electrically sound.  So I think I am in business.

Thanks,

Mark

[markmokris]

Well I am excited! I am tuning in stations!!!

I pulled out the oscillator coil and rewound the tickler with all your great advice. I put in back in the radio and finished wiring it up this afternoon. I brought it back up on a variac, and yes, I can turn in stations on the upper part of the AM band.

I actually had a dream about it last night in which I was showing a friend the radio and turned it on for the first time and stations came in. My dream came true !

The shadow meter even seems to be working.

As I tune down the band, it starts to cut out at about 1100. I was sure that it must be the oscillator dropping out, but I put my oscilloscope on pin 4 of the 36 tube and watched the oscillator signal. It seems to tune nicely across the entire band. It doesn't seem to be dropping out at all.

I have my cathode resistor at 8200 ohms. All bakelite blocks have been replaced, and I have pretty much checked most of the resistors.

I am wondering if I can impose upon all of you to tell me what I might try next. What should my strategy be?

Thanks!!!

Mark K8KZ

[klondike98]

Congrats!!! I just rewound my first coil, though mine was just the SW primary section on a 60MB antenna coil (only 4 turns), its a thrill when it works!
   

[Radioroslyn]

I would try a few things. Listen in on the osc with a xsistor radio( tune the 19 to 1MC and listen for the osc signal at 1MC+the IF frequency) Place the xsistor set near the mixer tube.
Double check the primary of the ANT coil. It can have the same fate as the osc had.
Check for bent rotor plates on the tuning condenser.

Terry N3GTE

[markmokris]

I discovered something significant. When I connect my 3 ft scope probe to pin 4, the cathode, of the 36 tube, the radio works really well. I can pick up stations across the entire band.

The scope probe is even disconnected from the scope. Electrically there is no connection on the other end.

I replaced the scope probe with 4ft of 2-conductor speaker wire laying on the floor (conductors connected together), and that also makes the radio work great. Same effect.

I sense that I am adding some "gimmick capacitance". What do I need to do to install this inside the set? Or any other suggestions?

Mark

[markmokris]

Second thought .... Maybe there is something wrong with the the first stage, th RF stage, and by a adding length of wire a at the oscillator, I am just picking up some signals I am otherwise missing?

Mark

[markmokris]

I have also posted this to the other place. I apologize if that is bad form .

Here is where I am at. I discovered that when I attach a 4 foot length of wire to pin 4 of the 36 oscillator tube, the radio works beautifully. I can tune in stations reliably clear across the band. I can hear a zero beat of the oscillator in a small transistor radio that I hold nearby.

As soon as I disconnect the 4 feet of wire, the oscillator stops. The zero beat in the nearby radio dies. Reception across the band dies. I discovered this effect originally when I tried to connect a scope probe to pin 4 and the radio started working.

I have played with 2 different values of the #10 resistor, both 13,000 ohms and 8,200 ohms. Neither seems to make any difference.

I know the oscillator in this radio can be very finicky. I have done the whole baking of the oscillator coil and rewind of the tickler. I have checked tube voltages. I also have a length of antenna wire connected at all times to the antenna terminal. Performance degrades when I disconnect that, of course, but the oscillator does not stop. However operation of the oscillator seems completely dependent on the wire I connect to pin 4 of the 2 tube.

Do any of you that have experience with the radio have any suggestions?

Thanks!

Mark

[markmokris]

I have checked both the antenna coil and the RF transformer which both precede the oscillator. They seem to have correct continuity at all points.

With the 4 feet of wire attached to the 36 tube, pin 4, and the oscillator oscillating, I disconnect the wire from the antenna terminal. Performance drops, of course, but the oscillator keeps oscillating. I can tell through the zero beat I hear in the transistor radio I hold up to the Philco. However, in all cases, when I disconnect the wire from pin 4 of the 36 tube, the oscillator cuts out. I no longer hear the zero beat in the transistor radio.

It seems like that wire connected to pin 4 is adding something. I don't know if it is acting like a "gimmick capacitor" or something like that?

I will keep experimenting. I know from much reading that the 36 oscillator circuit in the Philco Model 19/89 can be very finicky.

Thanks,

Mark

[klondike98]

Terry is much better at troubleshooting than I am so when he chimes in.... listen...but in the meantime, check block cap #8 to be sure its wired in correctly and has the right value.  The wiring is found here http://www.philcorepairbench.com/bblokcap.htm  I'm not sure which of the two caps in the 8174-B is in parallel with resistor #10, the 0.09uF or the 0.0007.  Since you rewound the oscillator transformer, its possible it may take a different value cap to make it oscillate.  That's my 2 cents 

[VE6ZRT]

Hello there...after having just worked on a model 19 ( Canadian version 319 chassis ) I can tell you that the capacitor value for the RC network for the oscillator was around 700pf ( less than 1000p for sure ). When you add a wire or probe to the network you are adding capacitance ( a few 10's to 100's of pf ). So since you rewound some of the oscillator coil it looks like you will need to add 100pf or so to compensate for coil inductance differences. If an additonal 100pf does not work then try 200pf...it should start oscillation with these additional values hopefully.

[Mondial]

Hi Mark. You might read through this thread about the restoration of an 89 (same basic chassis) with a similar osc problem. It seemed only to oscillate when a cliplead was connected to the 36 cathode. In the end he got it working, so you may find some useful info here:

http://philcoradio.com/phorum/showthread.php?tid=8400

Also, check if the tickler winding is in the right direction and start and finish are connected to the correct terminals. I seem to remember a case where the coil was connected wrong, but it still oscillated over a portion of the band.

[markmokris]

Hey Mondial,

Thanks for finding that thread again. I read through it briefly once before, but couldn't find it again. Now I read it more thoroughly.

I am wondering if I do have the tickler wrong. I wound it in the direction just like this article:

http://www.philcorepairbench.com/tips/svctip36.htm

I have the connection labeled "Start" on Pin 1 and the connection labeled "Finish" on Pin 2. But from what these guys are saying in the post, it is the opposite. I have it wound correctly, but the two ends of the coil go to the wrong pins.

I will trying switching the connections under the chassis between pins 1 and 2 and see it that makes the difference. I'll let know you.

Thanks!

Mark

[Radioroslyn]

Hi Mark
I've had them not oscillate at the low end of the band. What I've done is added a few turns to the feedback winding. As mention before I'd try flipping the connections at the magnet wire on replacement winding  first.
GL OM
Terry N3GTE