[Eric]

I have a Zenith 6S527 schematic here
 http://www.nostalgiaair.org/pagesbymodel...025231.pdf



I'm afraid I have screwed up the replacement of the E cap C15, C16 right now all I get is a hum so now I have to sort it out what I did my main question is about the polarity. Is the positive of 15 and 16 go to the field coil and the neg to the K of the 6X5?

[morzh]

No, it is opposite. FC has the minusses and the Cathode has plusses.

[Eric]

Thanks Morzh,
 wired this up this morning and get nice clean static the hum is completely gone (no stations yet) I will finish the recap.  From the whistling I hear this may need an alignment but see no procedure any ideas where I might find it?

Eric

[morzh]

Find any similar Zenith tube alignment procesdure, like here

http://www.nostalgiaair.org/pagesbymodel...025500.pdf

and use the similar approach.
All superhets are aligned in a similar manner, just location of the trimmers and padders are different.

[Arran]

That is an interesting arrangement, the field coil is parallel connected with the bias resistors on the negative side, in most cases, should they wire the field coil on the negative side it would be in series with the bias resistors, somewhere between the center tap and the chassis. I also noticed that the parts list specs most of the carbon resistors as 1/4 Watt, so you may want to check those over as you replace the paper caps, 1/4 Watts are more likely to drift upward in value then 1/2 Watt resistors, or go open, particularly if used as a plate load resistor such as R10, 220K Ohm. I would also check the bias resistors, R12 and R13, 1/4 Watt rating sounds way too low for those even if they are in parallel with the field coil, in most sets those would be 5 Watts at least.
Regards
Arran

[morzh]

I agree, I never saw that. I am not even sure I like that. But I guess it works.

[Eric]

Radio is done and refinished am works fine with stations up and down the dial but nothing on SW even with an extended antenna. Thing is I can't find alignment data anywhere Rider's doesn't have anybody point me in the right direction on this?

Eric

[morzh]

Eric, if you know the IF is 455 kHz, just put it through and align the IF xfmrs, then just align using low and high limits on the dial.

[Eric]

Thing is under the chassis are 4 trimmers besides the tuner trimmers (also under the chassis ) and the IF's are on top A,B,C&D
So there is 
E wavetrap padder found 
F broadcast padder osc
G    "          ant padder on tuner found.
J broadcast padder
K sw osc on tuner found
M sw padder antenna
Got a print from Radiomuseum and it shows the location of some but not all and no alignment procedure. So this is where I'm at hope to ID the rest and locate then go from there.

Eric

[tbone]

Try this schematic in the link below. The adjustments have the same labels as your model and are in same part of the circuit.

This is one of those models where you align the SW Osc at 18MHZ first followed by the BC band and then SW ant at 16 MHz last. SW Osc should be 455khz above 18 if using a counter. This way the image is 910 KHz below.

I often tune the SW ant for most ambient noise if you don't have a sig gen that goes that high.

I can tell you that if you don't have a good outside antenna, SW is pretty much dead lately. Look for WWV on 10 or 15 as they are a good reliable signal.

Hope this helps.

http://www.nostalgiaair.org/pagesbymodel...025201.pdf

[Eric]

Thanks Tony, This looks like what I'm looking for!

Eric

[tbone]

Hi Eric,

Did it work? Hopefully you’re enjoying the radio now.