I've got a small tube radio I'm working on that I just can't get the signal to be strong across the dial. One of my Cans (the first I.F)had a meltdown in the coils. I've replaced it with a similiar one off of a junk old radio, and for a time I felt like I almost had it aligned. But then I had a frequency garbled at about 650KHZ and only a weak station here and there. I'm considering changing the other IF can to match the one that I put in. Has anyone out there run into this kind of problem?

I'll be back with the names and numbers off my schematic.

Thank you! Thank you! Richard...Neal

I assume there are two IF xfmrs. They operate independent of each other. They each need to be tuned to the IF frequency. But if one xfmr is causing a problem, I can't visualize how changing the other one to "match" could possibly help.

How did the first xfmr get zapped?
Doug

I have had to replace IF transformers that were more sensitive at one end of the band than the other. I had sprayed down the chassis with solvent and some must have gotten inside the can and de-tuned it permanently.
The manufacturer-tuned caps for the IF windings were part of the IF can base and not serviceble. It is important to keep solvent away from these assemblies.
Anyway, I was able to find exact part number replacements at 'Playthings of the past'. After alignment, the radio is sensitive all across the band now.

: I have had to replace IF transformers that were more sensitive at one end of the band than the other. I had sprayed down the chassis with solvent and some must have gotten inside the can and de-tuned it permanently.
: The manufacturer-tuned caps for the IF windings were part of the IF can base and not serviceble. It is important to keep solvent away from these assemblies.
: Anyway, I was able to find exact part number replacements at 'Playthings of the past'. After alignment, the radio is sensitive all across the band now.

Thanks, I will keep that in mind...Neal
:

:I assume there are two IF xfmrs. They operate independent of each other. They each need to be tuned to the IF frequency. But if one xfmr is causing a problem, I can't visualize how changing the other one to "match" could possibly help.
:
:How did the first xfmr get zapped?
:Doug
:It happened while I was tuning it...Neal

:I assume there are two IF xfmrs. They operate independent of each other. They each need to be tuned to the IF frequency. But if one xfmr is causing a problem, I can't visualize how changing the other one to "match" could possibly help.
:
:How did the first xfmr get zapped?
:Doug

The original 2IF adjustments are bottomed out...Neal
:

::I assume there are two IF xfmrs. They operate independent of each other. They each need to be tuned to the IF frequency. But if one xfmr is causing a problem, I can't visualize how changing the other one to "match" could possibly help.
::
::How did the first xfmr get zapped?
::Doug
:
:The original 2IF adjustments are bottomed out...Neal
::
:

Hi Neal

IF Transformers are tuned to a fixed frequency. They should not effect one end of a band more than the other.

Here is what can cause this problem. The oscillator is tuned IF Frequency above station being received. If IF Transformers are set above the schematic frequency the osc is operating higher. The higher you go in frequency less capacity change is required to tune a fixed range of frequencies. Stations will be closer together on the dial and usually low end is weak.

Radios will either have a adjustable padder capacitor or the oscillator section tuner will be smaller than Antenna section. If a radio has a padder it should be set while listening to a station on the low end of the dial. Adjust for max volume while rocking tuning back and forth.

Some tuners have cuts in the outside plates. These sections are made to be bent to get best reception.

Norm

:I've got a small tube radio I'm working on that I just can't get the signal to be strong across the dial. One of my Cans (the first I.F)had a meltdown in the coils. I've replaced it with a similiar one off of a junk old radio, and for a time I felt like I almost had it aligned. But then I had a frequency garbled at about 650KHZ and only a weak station here and there. I'm considering changing the other IF can to match the one that I put in. Has anyone out there run into this kind of problem?
:
:I'll be back with the names and numbers off my schematic.
:
:Thank you! Thank you! Richard...Neal
:

:Hi Neal
:
: IF Transformers are tuned to a fixed frequency. They should not effect one end of a band more than the other.
:
: Here is what can cause this problem. The oscillator is tuned IF Frequency above station being received. If IF Transformers are set above the schematic frequency the osc is operating higher. The higher you go in frequency less capacity change is required to tune a fixed range of frequencies. Stations will be closer together on the dial and usually low end is weak.
:
: Radios will either have a adjustable padder capacitor or the oscillator section tuner will be smaller than Antenna section. If a radio has a padder it should be set while listening to a station on the low end of the dial. Adjust for max volume while rocking tuning back and forth.
:
: Some tuners have cuts in the outside plates. These sections are made to be bent to get best reception.
:Thanks Norm, I've seen the cuts and the adjustable padder.

This is an ARVIN radio, model #544 or 544a. I think I will go ahead and put in matching IF Cans 1st. Then we'll see...Neal
:Norm
:
:
:
::I've got a small tube radio I'm working on that I just can't get the signal to be strong across the dial. One of my Cans (the first I.F)had a meltdown in the coils. I've replaced it with a similiar one off of a junk old radio, and for a time I felt like I almost had it aligned. But then I had a frequency garbled at about 650KHZ and only a weak station here and there. I'm considering changing the other IF can to match the one that I put in. Has anyone out there run into this kind of problem?
::
::I'll be back with the names and numbers off my schematic.
::
::Thank you! Thank you! Richard...Neal
::
:

Good explanation Norm, Thanks again...Neal

:Hi Neal
:
: IF Transformers are tuned to a fixed frequency. They should not effect one end of a band more than the other.
:
: Here is what can cause this problem. The oscillator is tuned IF Frequency above station being received. If IF Transformers are set above the schematic frequency the osc is operating higher. The higher you go in frequency less capacity change is required to tune a fixed range of frequencies. Stations will be closer together on the dial and usually low end is weak.
:
: Radios will either have a adjustable padder capacitor or the oscillator section tuner will be smaller than Antenna section. If a radio has a padder it should be set while listening to a station on the low end of the dial. Adjust for max volume while rocking tuning back and forth.
:
: Some tuners have cuts in the outside plates. These sections are made to be bent to get best reception.
:
:Norm
:
:
:
::I've got a small tube radio I'm working on that I just can't get the signal to be strong across the dial. One of my Cans (the first I.F)had a meltdown in the coils. I've replaced it with a similiar one off of a junk old radio, and for a time I felt like I almost had it aligned. But then I had a frequency garbled at about 650KHZ and only a weak station here and there. I'm considering changing the other IF can to match the one that I put in. Has anyone out there run into this kind of problem?
::
::I'll be back with the names and numbers off my schematic.
::
::Thank you! Thank you! Richard...Neal
::
:

:I've got a small tube radio I'm working on that I just can't get the signal to be strong across the dial. One of my Cans (the first I.F)had a meltdown in the coils. I've replaced it with a similiar one off of a junk old radio, and for a time I felt like I almost had it aligned. But then I had a frequency garbled at about 650KHZ and only a weak station here and there. I'm considering changing the other IF can to match the one that I put in. Has anyone out there run into this kind of problem?
:
:I'll be back with the names and numbers off my schematic.
:
:Thank you! Thank you! Richard...Neal
:

Hi Neal

What is meant by 2 - 35Z5's fading away? A 35Z5 supplies B+ voltage. Does voltage on pin #8 go down?

Measure pin #5 from pin #8 of your 50L6, audio output tube. Pin #5 should remain around 5 volts negative. If it goes positive the tube will draw high current and distort.

Norm

::I've got a small tube radio I'm working on that I just can't get the signal to be strong across the dial. One of my Cans (the first I.F)had a meltdown in the coils. I've replaced it with a similiar one off of a junk old radio, and for a time I felt like I almost had it aligned. But then I had a frequency garbled at about 650KHZ and only a weak station here and there. I'm considering changing the other IF can to match the one that I put in. Has anyone out there run into this kind of problem?
::
::I'll be back with the names and numbers off my schematic.
::
::Thank you! Thank you! Richard...Neal
::
:
:I've completed the exchange of IF cans. Now the two cans match. I have no trouble finding the signal from my signal generator and tuning it. The alignment seems to go Ok, but I can not get a pure tone. It has a little noise with it. And when I search for stations after alignment, I can only find a few on the low end. I'm cleaning my IF coil pads, but I don't know what else to do.
:
:Also, I have two 35Z5 rectifier tubes that I can exchange with one another. They will both fade away down to no output then slowly come back online. I think it's a dirty socket, but what do you guys think?...Neal
:

Hi Norm,

What I meant was the radio would loose all power to the tubes in a fading manner, then shortly after they would regain power and slowly come back to normal. It would do it with 2 different 35z5's so I knew it wasn't the tube. What it turned out to be was oxidation on the tube socket. I fixed it with a little deoxit.

I replaced the 2nd IF can (and coils) with one that was a matched set with the 1IF that I put in cause the original burnt up on me while I was attempting to align it. That gave me better adjustment range on the two of them. Remember the original 2IF was bottomed out on adjustment. That gave me the adjustment range for the IF Frequency, but I still had noise on the 1IF during adjustment.

So I took that one apart and found a blue residue between the plastic (Is it Milar?) and the metal plates. Apparently someone before me had lubed it up hoping to help the situation. I cleaned up the milar and the metal plates and put it back together. Voila! I have a winner! After aligning the signal at 1400KC, no more noise, and stations wide accross the whole band.

I want to thank everyone who responded to my post: Doug, Walt, you Norm, and if I have forgotten anyone, you too.

Next comes a Zenith. It's on the back burner. I'm sure I'll be posting problems with that...Neal

Hi Neal
:
: What is meant by 2 - 35Z5's fading away? A 35Z5 supplies B+ voltage. Does voltage on pin #8 go down?
:
: Measure pin #5 from pin #8 of your 50L6, audio output tube. Pin #5 should remain around 5 volts negative. If it goes positive the tube will draw high current and distort.
:
:Norm
:
:::I've got a small tube radio I'm working on that I just can't get the signal to be strong across the dial. One of my Cans (the first I.F)had a meltdown in the coils. I've replaced it with a similiar one off of a junk old radio, and for a time I felt like I almost had it aligned. But then I had a frequency garbled at about 650KHZ and only a weak station here and there. I'm considering changing the other IF can to match the one that I put in. Has anyone out there run into this kind of problem?
:::
:::I'll be back with the names and numbers off my schematic.
:::
:::Thank you! Thank you! Richard...Neal
:::
::
::I've completed the exchange of IF cans. Now the two cans match. I have no trouble finding the signal from my signal generator and tuning it. The alignment seems to go Ok, but I can not get a pure tone. It has a little noise with it. And when I search for stations after alignment, I can only find a few on the low end. I'm cleaning my IF coil pads, but I don't know what else to do.
::
::Also, I have two 35Z5 rectifier tubes that I can exchange with one another. They will both fade away down to no output then slowly come back online. I think it's a dirty socket, but what do you guys think?...Neal
::
: