Would this be the easy cure for silver mica disease? I know it won't perform as well.
But for a plastic radio, just so it will still pick up local AM, I have often wondered why someone would spend the time and $$ on replacing the interstage transformer.

Not a feasible "fix" since bypassing the IF filter would reduce the set's sensitivity and selectivity to where it would be useful only as a doorstop: if you got any stations at all, they would be extremely powerful ones and they would be piled on top of each other, making for a very frustrating listening experience.

By the 1940s, inexpensive radio manufacturers had perfected the recipe to produce sets at rock-bottom costs. Even these cheap superhet radios (sometimes called the All American Five, or AA5, in reference to their tube count) had tuned IF stages. If there had been any way to eliminate this stage while retaining acceptable performance, someone would have done it.

Hi CV,
Have you ever seen those 'Lone Ranger' radios. On eBay they sell for a pretty good price. I looked up the schematic for the model (Majestic 104). The radio is real crap. It has no IF stage. The 12BE6 output goes through an IF transformer then strait to the detector. It has no other gain than conversion gain.
That is cheap! I am sure the regular radio buying public wouldn't have put up with such performance. I suspect many boys were disappointed that they couldn't receive the Lone Ranger on their Lone Ranger radio.

Best regards,

Bill Grimm

Bill,
Yes, that IS a cheap radio- no IF gain stage (tube amp) at all! However, it still has an IF transformer to select the 455 KHz signal, so it would still have a measure of selectivity (although it probably was a real dog due to low sensitivity).

If I understand the original post correctly (and I may have misinterpreted it) the poster was asking if it was possible to "snip out" the IF transformer entirely and go directly from the converter output to the detector via an RC coupling. Don't think so- although the Lone Ranger set is just a small step above that! Any simpler and you'd have a single-stage TRF set.

:Bill,
: Yes, that IS a cheap radio- no IF gain stage (tube amp) at all! However, it still has an IF transformer to select the 455 KHz signal, so it would still have a measure of selectivity (although it probably was a real dog due to low sensitivity).
:
:If I understand the original post correctly (and I may have misinterpreted it) the poster was asking if it was possible to "snip out" the IF transformer entirely and go directly from the converter output to the detector via an RC coupling. Don't think so- although the Lone Ranger set is just a small step above that! Any simpler and you'd have a single-stage TRF set.
:
I have owned do not have now am radios with only 4 tubes AA4, 3 other tubes besides the rectifier tube, what tube was left out?

The All American Five tube complement broke down as
follows:

1: Converter/Oscillator tube
2: IF Amp
3: Detector/1st Audio
4: Audio Output
5: Rectifier

Tube types varied with the era of the set, going from octal-based tubes in the 30s to miniature tubes in the late 40s through to the end of tubedom.

Can't say that I've ever heard of an "All American Four".

There was plenty of cheap radios with only 4 tubes. Such as the Westinghouse shown here.

http://radioattic.com/item.htm?radio=1090415

And all of the Arvin metal midgets.

:There was plenty of cheap radios with only 4 tubes. Such as the Westinghouse shown here.
:
:http://radioattic.com/item.htm?radio=1090415
:
:And all of the Arvin metal midgets.
:
:
Speaking of coupling, I had a Crosley that only had 1 IF transformer. Was this done to save cost and at least have one stage of selective coupling? Could the circuit be modified to include a second IF?

http://www.nostalgiaair.org/PagesByModel/494/M0003494.pdf

Hi John,
Adding an IF could be done. There would be problems to overcome. The first would be space, where to put the new tube and IF transformer. I am not sure the impedance of the original IF transformer would be right, so that may need to change out, too.

For the record, this is a good Description of the AA5 set.
http://www.radiophile.com/adm3725r.htm

The AA4 (I, too, have not heard the term before) omitted the IF amplifier tube. This tube typically provides the lion's share of signal amplification.
The AA6 had an RF section ahead of the mixer. It would be the same type of tube used for the IF.

As mentioned before it was done to reduce cost and/or size. The Lone Ranger sets were sold to fit into a child's crowded bedroom. It was small in size.

All the Best,

Bill Grimm
http://www.radiophile.com/adm3725r.htm