My old Philco 500 seems to be working better now after replacement of several capacitors. It does need alignment especially on low end of dial.

Does anyone have a schematic for this 1956 transistor radio? Any suggestions on alignment procedure?

Thanks

Hmmmmm....found a few 47ufd--->1/4 ufd and 100ufd---> 1ufd old electrolytic units that had developed problems in the unit ehhh? Pity that you didn’t have an ESR meter to evaluate all units.
I see nothing on that units in Sams, but I can give you some universally applicable seat of the pants info on AM xstr radios that should suffice when having to "work in the blind".
What you might do first is evaluate the overall cross band sensitivity of the unit. In the lab I would inductively couple the unit up to a Noise Comm wideband noise generator source and tune the radio completely across the AM band to evaluate. Your not having that access will mean that the YI factor will have to be utilized instead.(Yankee Ingenuity). In which case, you take the unit to the very close proximity of a fluorescent lamps envelope proper until you start picking up strong AC hash on the receiver when off station and then tuned from one end of the AM band to the opposite end. [NOTE: that the old style of lamp with the iron ballasts will be THE preferred unit...... The new CFL units of the sizes of conventional incandescant bulbs probably will just not work for you, with their internal electronic "ballast" operating in the mean freqs of 30-60hkz...in which case they will just give you heterodyning "birdies" as you tune across the band. That is NOT what we want, we want noisy HASH, so you just may have to locate the preferred type of lamp/ballast combo. Once you are getting the noise pick up it can then be attenuated, as required, by merely distancing the radio with its encased internal ferrite bar loop antenna farther away from that broadband noise source.

Brass Tacks:
I am now working blind on that specific unit but I would think that one would be involved with confirming 7 alignment adjustments max.

Loop antenna:
Typically a form overwound with Litz wire and located ~1/4-1/3 from one end of the Ferrite bar. A light wax over coating typically holds it into position and the coils lateral position determines its inductive tuned value.

Oscillator Coil:
Typically an alum can shielded inductor with a central cross slot slug that is adjusted with a plastic/bakelite/fiberglass tool so as to not detune on final adjustment, when the tool is moved away. This may also have a light wax over coating.

Tuning condenser:
Expect this to be of compact interleaving plate design with the addition of plastic poly sheeting between plates vice the conventional air gap spacing
of conventional large air units. The poly enhancing the capacitance, to make a physically smaller unit….no inner plate shortings either…..unless one runs its wheels off ….. with voluminous use .
There will be its Osc section and its RF section along with the adjunct (screwdriver slotted adj) Osc and RF variable padder condensers.

IF transformers (Typically 3):
These probably will be of the same mechanical construction / appearance as the aforementioned oscillator coil housing. Same single cross slotted slug and probably light wax coating overlay.

The latter IF’s probably / hopefully will not need any adjustment at all. That is, if the unit had not previously been “diddled” with by an uninitiated novice….turning everything on the unit. A slugs “cracked” wax overlay leaves some clue as to whether an adjustment had been attempted after factory alignment.

Initial evaluation:
Bring the radio close enough to the lamp to get a “static whine” from the radio and then tune across the band to see if there is an approximately equal “hash” level across the band. If it seems to be concentrated at either the high end or low end of the band, some touch up may be in order for broadband tracking enhancement.
Typical adjustment of a slug will usually only be a rotary touch up movement the width of an adjustment slot. To be on the safe side, it never hurts to mark a slugs initial “found” position with a distinct fine Sharpies hash mark line. The same is true for the slotted padder condensers on the
variable tuning capacitor.
Compensation:
The initial consideration would be the RF aspect of adjustment . In that situation the tuning condensers RF padder adjustment is used to optimize the reception at the high frequency end ~1400Khz of the AM band. Its companion RF adjustment at the low ~600Khz end of the AM band is made by adjusting the inductive value of the Ferrite loop antenna. It sometimes requires a blow dryers warming air to soften and free the wax over lay aside to get the coil form mobile enough to be able to slide / adjust it.
The other two adjustments would involve the adjustment of the oscillator coils slug/inductance for optimal tracking at the low end of the AM band and the variable tuning condensers oscillator padder condenser for optimum tracking of the high end of the AM band.
The latter two adjustments bear a hazard on a large dial scaled radio, as the variance of too great of a tuning shift would show up as an introduced error in the dial scale calibration **. Hopefully, a well designed receiver should not show this, as optimal reception performance and calibration should be in congruence. However, on your transistors micro sized dial , there is certainly some lee way with its having very few freq hash markings at all !

Overall:
Here would be my quickie alignment / tracking adjustment.
Initially find 1400 and 600 on the dial scale and tick mark with a blue Sharpie.
Bring the radio to the lamp and orient the loop for adequate off station
“Static / hash” and note if the response is uniform across the band. If so, up the volume to max and back away from the lamp just enough to get a discernible hash with the newer lower level noise source. Then see if the radio is still having the same cross band performance. If all was then well the only thing extra that I would do would be to tune it to ~1100 Khz . Then mechanically place the radio so that it would not be moved during adjustments. Peak the three IF transformer slugs for max hash/noise.
That usually does not encompass a rotary slug movement in excess of the width of the slugs cross slot.
If by chance you needed to correct tracking due to non-uniform noise across the whole AM band, you optimize to the sets designed limitational capability by utilizing:

Tuning cap’s RF padder change-----for high end of AM band optimization
Ferri-loops coil positioning-----------for low end of AM band optimization
Osc inductance change ----------------for low end of AM band optimization**
Tuning cap’s Osc padder change----for high end of AM band optimization**

“Searching in the blind” Tips:
For osc coil location…first of all, expect it to be in close proximity to the tuning cap.
Also, sometimes possible to tune into a clearly received… yet weak station and sometimes the extra inductance of a ferrous mini screwdriver blade into the slug will skew the osc to detune from the station slightly. If not… Sharpie mark the slug and detune slightly to see if the station shifts off. Eureka...you have then found the osc coil/can.

Same procedure on the Osc padder of the variable capacitor where just the hand held screwdriver blade touching the metal along with your added stray hand capacitance should shift you off station. Therefore, the OTHER padder is the RF padder.
The 3 IF’s are sequentially arranged even though their required cramped physical locations may require a serpentining or offsetting placement.

73’s de Edd

Just an additional word of caution. You may be tempted to use a metal screwdriver on those sloted ferrite cores. Don't do it. They crumble or crack in half very easily. Before you diddle, mark the slot location on the tiny tin can. Unless somebody has already diddled, you should not have to turn it more than a 1/4 turn.

MRO

This is true.

As I recall, there was a red can that affected the dial linearity in most transistor sets.

Using a metal tool may also affect the electromagnetic field in the cans and cause slight misalignment. Plastic and fiberglass composite tuning tools are ~ or were ~ available for this purpose.

If someone has "tightened the screws" as we used to say, they should be realigned.

Hope it helps.