[Eric]

I have a Stewart Warner R-136 chassis it is also labeled model 1361-1369 Ferrodyne.
Alignment and Schematic http://www.nostalgiaair.org/PagesByModel...020359.pdf
Riders 7-4 & 6-18
Tubes all tested good
I have recapped and replaced all the dog bone resistors that were more than 20%. #13 a 300 ohm resistor was missing and the set would do nothing until I add that resistor.

Now I do get one very clear station 680 a number of weaker stations throughout the dial. I should get 750 as this is a big station here near Atlanta but I can barley hear it.
I have followed the instructions for the IF alignment and the broadcast calibration and b'cast band alignment but get no where. Have not tried any of the SW alignment.
One of the questions I have is there are 3 terminals on the back A,D,G currently D&G are shorted together with a clip. Should I leave this in place for the B'cast band cal?
I did not look at the Mica caps should I?

Eric

[morzh]

I think it does not matter if you have them connected or not during the alignment if you use regular antenna input and GND.

Have you checked how the AVC voltage behaves when you have that local station that is supposed to be loud?
Also do you have a spare 6A8 to try?

[Eric]

Morzh
I think I have another 6A8 and will try it in the morning, The print lists the 6H6 for the AVC but the socket voltages are 0 except for the heater. What pins should I check and what voltages should I see?

[morzh]

The centertap voltage of the transformer that feeds the 2nd det 6H6 (cold be tapped at the top of the volume reg) is also the AVC. When the station is strong you should see the voltage becoming more negative.

[BrendaAnnD]

Your socket voltages on the 6H6 would all be zero volts in that circuit. Your AVC voltage is developed across the volume control. Check across the top of the volume control and ground. The voltage will change with the strength of the stations. It should be somewhere around -1 to 2 volts when not on a station at all, and perhaps as high as -14 volts or so on a strong station.

[Eric]

On the 6H6 pins
pin off station xx on station
1- 0 xxx 0
2- 0 xxx 0
3- -.3 xxx -3.4
4-0 xxx 0
5- -.3 xxx -4.3
6x xxx -----
7-6.1ac xxx 6.1ac
8- 0 xxx 0
took a set of socket voltages, some were a little high like 6f6 pin4 screen grid calls for 245v I get 294 this is pretty much uniform through all the tubes on the plate and screen grid pins.
The 6J7 on the screen grid is 43v and should be 3v this is the biggest discrepancy on the socket voltages.
Brenda
On the vol control I get on the tap that goes to the tone control I get a -.4 when not on a station and -5 when tuned to the strong station with the vol turned about a 1/4turn pretty loud.

[morzh]

A dum question- have you checked all your coils continuities?
And have you checked the voltages?

[Eric]

Not a dum question and that's probably where I should go next? The IF(1&2) coils are very responsive so is the broadcast osc (3) and 4&5 only #6 the broadcast osc series padder doesn't appear to do much. I would think an open coil and they wouldn't do anything? I will start and check them one at a time.

[Eric]

Gone through about half the coils so far no problems

[morzh]

One of Murphy's deirvatives states it is likely to be the last one you check.

[Eric]

That Murphy guy I know him well! His cousin is known as the Law on Unintended Consequences

While poking around on what I believe to be #32 osc coil the padder screw appeared to be stripped which I think I may have helped along so I repaired that and noticed the mica cap. It has a single arrow when held with the arrow pointing to the right the colors are brown, brown, black reading left to right I take that as 110 am I right? It reads on my meter reads 27 should I replace?

[morzh]

You un-soldered it and then read it, right? not in-circuit?
Well, what kind of meter you got? capable of measuring down to 10pF or so?
What does it show when you put it on -||- and then just let the leads hang freely without touching anything?

Both my meters will show 0.1nF when unconnected.

Then you simply touch your cap (out of circuit or with one lead fully unsoldered AND without touching it with your hands as it will distort the reading considerably), and deduct whatever the meter was showing before from the reading.

Your cap is likely 110pF. If say your meter shows 0.2nF and then shows 0.31nF when touching the cap, it is good.

[Eric]

I'm using an elenco LCM-1950 the meter reads .007nf not connected leads open hanging in air scale is 4n
the cap assembly is removed from the ckt and the padder screw is removed and the plates are not touching
checked against a new silver mica rated 100pf and it reads .110nf
the mica cap reads .027
Does that mean the cap is reading 20pf?

[morzh]

yes it does.

But. Brown-Brown-Black I think is 11pF. (I though 110 but the the third number is the multiplier and the Black is =1, so 11 times 1 is 11pF)

Try to read the meter before you touch the cap while having the probes in hands, see if it shows more like a 16pF or so.

BTW what is the position on the sch and what does the parts list call for?

[Eric]

So if it were brown, brown, brown that would be 110?

It shows .010n holding the leads so the cap is really about 17pf and ok