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Solved****Crosley 515, no sound

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Solved****Crosley 515, no sound - Page 2 Empty Re: Solved****Crosley 515, no sound

Post by Ben Delk on Wed Sep 19, 2012 8:45 am

Thanks Cliff. I work at church on Wednesday nights so I'll get I'll back to you in the next few days.
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Post by Ben Delk on Thu Sep 20, 2012 9:03 pm

Cliff here's my reply to your questions:
"Speaker voltage look good and a did the "quick speaker test" pulling the output tube with power on, ok. "
This needs clarification. Saying speaker voltage looks good---Where did you make that measurement?—
Checked on 6B5 output, P1
note:
Before starting this process I cut and marked all 4 wires leading from the chassis to the speaker.

There are four different coils in the audio output section shown in the schematic .
Look at the two top ones inside the dashed outline of the speaker.The second one ( of the two) on the right is the voice coil winding.

Then there is the field coil on the left also a integral part of the speaker frame. It is usually several thousand ohms, it uses DC to magnetize the speaker poles in place of a permanent magnet. It has the black and yellow wires connected.

The two second coils below that are the audio transformer primary marked with a brown wire and a green wire that is the primary that is connected to the last audio tube plate, it is usually high resistance. (P1)
Green wire (goes to the(6B5, P1 plate) and the brown wire looks like its connected to a yellow wire at some point this is a common tie-point for the two different wires.
Correct, the brown wire connects with the yellow wire (speaker wire) both connect at one end of the cadnium.

Then you have the secondary winding coil that is used to match the impedance of the third (the speaker voice coil) that speaker coil usually measures between 3.2 and 8 ohms (sometimes as high as 16-32 ohms), when disconnected from the secondary winding

There are a couple of measurements you can make with a voltmeter, but be very cautious in you are dealing with fatal voltages on the tube plate. Turn the radio on and see if you have at least 200volts DC on the plate (P1) and on (P2) 210volts and then ZERO volts on both the cathode and grid.
6B5 output P1 = 280vdc
6B5 output P2 = 240vdc
K= -100mv
G = -90 mv

If you do then turn off the radio. Then disconnect the radio and wait for the filter caps to discharge. Then disconnect the primary wire on the audio transformer to the plate of the audio tube. Do a resistance check on the wire itself, you should show it as zero Ohms (full continuity, it was .3 ohms) so between the end of the wire and the transformer ground wire you should see maybe a thousand or more ohms. If so the primary winding is not suspect. Reconnect and then disconnect one of the secondary leads that goes to the speaker voice coil. You have two wires on the secondary, one of them needs to be disconnected at the speaker solder tab. When you connect your ohm meter to the unsoldered wire then connect the other lead of the meter to the still soldered terminal. You are then measuring the secondary winding resistance of about 3-16 ohms (it was 3.2 ohms). If you get no reading then the voice coil is bad. If so then you need to repair the speaker or replace. That becomes a problem. you could wire in an external mounted speaker .
When I reconnected the speaker I did test to be sure the speaker cone popped out then when power was applied.

Where did you loose the audio signal with the signal tracer in the path to the speaker? That will be a very big clue. Since you have a signal through the detector it sounds good to that point, so the previous sections are not at fault.

My signal tracer has an onboard speaker, with the ground from the probe connected to the chassis
I can touch the probe to most the pin on the IF and osc tube and the caps connected to them. Sorry I did not make notes on the pin number but I’ll get that next time. It is pretty safe to say when I touch anyway but the 6d6 tube pin connection or osc coil connections the music stops.

I have tried to check and re-check my solder connection and parts replacement for error. It looks ok but all this leads be to believe it is human error. Where do we go from here?
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Post by Resistance is Futile on Thu Sep 20, 2012 11:42 pm

The grid voltage should be negative according to your reading, so the tube is biased correctly.

The speaker coil reading is fine.

The reason the music stops on the oscillator is your tracer is acting as an extra capacitance and making the oscillator change frequencies. Don't worry about the oscillator, its working or you wouldn't get any music.
--------------------------
This part doesn't make sense to me at least, you need to read this and elaborate what you meant.

It is pretty safe to say when I touch anyway but the 6d6 tube pin connection or osc coil connections the music stops.
when you touch anyway do you mean touch your probe anywhere?

and then you say
but the 6d6 tube pin connection or osc coil connections the music stops. Do you mean no matter what connection you touch with the probe, you get no audio at all?, but the music is still detected when you touch the oscillator ? or when you touch any connection on the 6D6 tube connection?. With the exception of the filaments.

Sorry for being so specific but you understand not being there and all. I will review the schematic and your statements again.

you should get a signal on the audio plate then you know that tube is functioning right. If not then go one step back and probe the grid. If you get a signal then its somewhere in the tube circuit, maybe an out of tolerance resistor or a cap that is leaking or open or shorted. Another possibility is you could have reversed the leads on a capacitor or miswired them or wire or resistor. A resistor could be open or too high or (just a remote possibility of being low in value)

The best way is to understand, that schematics may be printed incorrectly and in following them, someone may have miswired it and gave up repairing it.

The easiest thing to do is make a second copy of the schematic and use a red pencil or marker pen on the schematic and go step by step from each wire traced and then mark each path as you trace from point to point. If you run across a different part or value then the schematic has then it requires some detective work by looking at comparable schematics, but also understand that companies used what was the cheapest to buy and had to modify a circuit to compensate too without changing diagrams.

Oh it helps when answering use Italics so I can see your responses easier.
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Post by Ben Delk on Fri Sep 21, 2012 9:09 am

Wow…that was a mess wasn’t it. Ok it should have said……………..
*It is pretty safe to say if I touch anywhere but the 6d6 or 76 tube pin connections or osc coil connections the music stops.
Do you mean no matter what connection you touch with the probe, you get no audio at all?
*if I touch anywhere but the 6d6 or 76 tube pin connections or osc coil connections with the probe I get no music. but the music is still detected when you touch the oscillator?
*I get music thru the sig tracer speaker when I put the probe on a couple of the osc coil terminals.
or when you touch any connection on the 6D6 tube connection?
*Correct.
With the exception of the filaments.
Correct
I have made a pdf document with a picture of the inside of the chassis and added arrows and notes. Also something just cross my fieble mind.....some of the old paper caps were double ended with center connections and I may have them grounded incorrectly. I'll recheck them this weekend and give you the cap schematic reference #.

https://servimg.com/view/17421296/54
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Post by Resistance is Futile on Fri Sep 21, 2012 4:37 pm

Now were talking turkey LOL
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Post by Ben Delk on Mon Sep 24, 2012 8:52 pm

Ok Cliff here's what I have so far.
[i]checked with meter all wires and resistors, point to point...ok
[i] test all caps with cap test unit, ...ok
[i] swapped tubed 80, 76, 6b5, no change

Going back over the schematic again I think I may have come across something I need to check again. Originally there was a double connection cap between the 76 tube pin2 (11Y=.03 mfd) and pin4 on the 6b5 tube. The second connection was 76 tube pin2 (11Z =.001mfd) and the electrolytic cap (6Y=6mfd). These two may be reversed. I'll update you when I get a chance to recheck it later in the week.
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Post by Ben Delk on Thu Sep 27, 2012 7:47 pm

rechecked connection, even tried reversving them just in case I might be wrong....no change. Any more suggestion. I'm about at the end of my patience with the *urd........
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Post by Resistance is Futile on Fri Sep 28, 2012 4:30 am

Crosley 515, no sound
by Ben Delk on Thu Sep 13, 2012 5:18 am

http://www.nostalgiaair.org/Resources/373/M0003373.htm

Picked up a Crosley 515 recently, not working of course,
1. Replace all the caps,
OK
2. checked the resistors.
OK
3. Powers up but no sound.
OK
*****The speaker coil and intermidiate transf both have power on them.

That means nothing the way you state it. You have to be more specific.
The speaker has two sets of connections.
One set is for the voice coil that is connected to the secondary of the audio transformer. This must be tested with an ohmmeter. This can only be tested by disconnecting and testing first the voice coil for continuity.

Then Test the secondary for continuity. Both should be good. If not the speaker or the audio transformer must be replaced or substituted.
-----------------------------------------------------------------------------------------------------


********If I get close to the speaker I can hear a slight hum but that seems to be more from the voice coil i think.
You cannot assume this. unless the above test is done first.

********The speaker has 1 small hole but the spider in the center has 3 legs and all are broken so I'll need a new spider unless I can find a way to replace the legs.

That is a big clue to speaker problems. The speaker must move freely without restriction other than limited free travel. If you hear any rubbing of the speaker then its no good. If you hear faint audio and I don't mean Hum then the speaker is getting some signal but since its mechanical binding it will suppress the sound to being very faint. You may hear some buzzing. That is also the voice coil being restricted or warped.You then must hook up a good PM speaker
-----------------------------------------
If I connect my signal tracer to ground and touch the probe to the top of the 6d6 IF tubeI get great sound out of the tracer speaker and I can adjust the voulme control on the radio and it goes up and down.
OK that means you have signal at that point.
-----------------------------------------
Same if I put the probe on the Osc 6d6 tube top.
OK that means you have signal at that point.------------------------------------------
I check the continuity from the ocs coil to 1st IF trnf to grd, 47.5k.

From osc coil thru 1st IF trnf to the cadeum groud, 20.9ohms.
What is "cadeum groud" common ground? chassis ground?
Skip the reading for resistance right now.

-----------------------------------------
Use the ****TUBE SOCKET VOLTAGE READINGS**** on page 6-12 and remember these readings must be within 10%, This must be done to get the correct loaded meter voltages. If you use a modern DVM or ohmmeter such as a Simpson 260 they have a 20,000 ohms per volt and your readings will be higher than the chart.
If the voltages at any point are incorrect you must replace components to correct. If the voltage is to low either you have a low resistance or short. If the voltages are too high you have a capacitor that is open or a resistor that is too high in value or also open.
-----------------------------------

Went back over all my solder connections, OK.

Thoughts?
They must be mirror shiny, if they are frosted or dirty you have a bad solder joint, those are called cold solder joints. If they have peaks of solder then they too indicate a cold solder joint. This will add to the problems of unwanted resistance or bad electrical readings

Re: Crosley 515, no sound
by Bill Cahill on Thu Sep 13, 2012 7:55 am

My guess would be silver migration of built in caps in one, or, both of the I F transformers.
Check your secondary voltage. It should be 0, or, a low negative voltage. If you get a positive voltage, there is your culprit.
Bill Cahill

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This is also important on voltages of biasing to the next tube as Bill mentions.
Silver Migration can be a problem, but with you getting a signal that is remote at this point but a valid observation and another clue to follow up on if necessary.
___________________________________________


Re: Crosley 515, no sound
by Ben Delk on Thu Sep 13, 2012 8:09 am

If it is "sm" is there a reasonable fix?
Removing and cleaning or replacing the caps if a problem.
-----------------------
I'm assuming IF trnfsm secondary voltage , correct?
See Bills response above on IF voltages on secondaries

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Re: Crosley 515, no sound
by Bill Cahill on Thu Sep 13, 2012 9:39 am

Ben, what do you mean by "SM"?
Yes, I mean the I F transformer secondaries.
If you have any Positive voltage there, transformer is bad.

Let me tell you.
I have an Emerson AM radio. I re capped it.
Tried radio. A hum. I turned up volume control, and, saw it sparking. Oh, oh!
Put my meter on it, and, got positive 35 volts on it. I quickly turned it off. I replaced transformer. Problem solved, radio plays.
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Re: Crosley 515, no sound
by Ben Delk on Thu Sep 13, 2012 10:33 am

"SM"....sliver mica".
I found an article on cleaning"sm" and installing new mica caps underneath the if trnfm.
Ok, I'll keep checking stuff.
Thanks

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Number of posts: 147
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Registration date: 2012-04-03

********************************
I am going to stop at this point and go to bed, will try to pick this back up tomorrow or day after if possible.

Please check you spelling and grammar, it helps us to not have to say, "what did he mean or say?"

Example: *****The speaker coil and intermediate transf both have power on them.

This (intermidiate transf) means nothing the way you state it. If you were referring to the I.F. transformers it still means nothing as you need to discuss one item at a time especially since there are usually two I.F. transformers . Try to stick to one part in the same sentence or paragraph that way we don't get confused in all the details.
The speaker has two sets of coils,
1. A voice coil and
2. audio transformer with two coils-a primary coil and a secondary coil.
3. Then there is a coil that provides magnetism for the speaker and this is referred to as the field coil.


*********************************************************************************
Somewhere on my forum I have a way to do schematics and I will see if I can find that and reference you to that.:
http://sparks-radio-shack.forumotion.com/t61-how-to-find-those-bugs-with-a-red-pencil?


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Post by Wildcat445 on Sat Sep 29, 2012 1:06 am

Cliff and Ben,

I have been following this project from the beginning. At first, I thought this was going to be one of the old "I bought an old radio. I threw some parts at it. I plugged it in. It smoked. What's it worth" type thread. But, I have found this to be an interesting project. It got even more interesting when I took the time to print the schematic.

The schematic I printed is in Riders 6-11. It is dated October, 1935, but the design of this radio chassis reminds me more of an old TRF from the '20's than a super-het from the late '30's. I thought for a moment that it was a TRF, until I saw that it had IF transformers. Man, what an antique!

The first thing I noticed was that the volume control is in the antenna circuit, instead of being the input to the audio section. It varies the gain of the IF amplifier. Next, this chassis utilizes a 76 triode for a detector. I don't believe I have ever worked with a circuit like this, and am certainly not sure how it works. Usually, you see a 6H6 duo-diode or similiar as detector, and then the 76 as an audio amplifier and AVC amp. Then, there is a phono input that is fed to the cathode of the 76, and the radio signal is fed intothe grid of the 76. No switch to kill the radio when using the phono? Strange. Speaking of AVC, I still don't know how it works in this chassis.

The audio section appears to be the 6B5 tube. Period. This tube apparently works like a half-a$$ push pull circuit. I have never worked with a circuit like this, either. Interesting.

My opinion is that this is not the best radio for someone faint of heart. I agree that the next step is to sub a permanent magnet speaker to eliminate a rubbing voice coil as the problem. My feeling at this point is that if the voice coil were rubbing that the complaint would be low output or distortion. A silent speaker is usually caused by something else. An open voice coil, maybe.

The problems that Ben is having are multi-faceted. Lack of a disciplined diagnostic procedure, lack of technical expertise and the lack of the ability to articulate same, a radio with an unconventional circuit, and the lack of parts for substitution. He seems to be jumping all over the place and grabbing at straws. Better to develop a good diagnostic procedure, make accurate notes, and take a stage at a time. If you are getting a signal with your signal tracer, go to where the signal ain't. Then start the troubleshooting from there. Injecting a 400 cycle audio signal into the grid of the 6B5 would not hurt anything either. I am still not completely sure what you have found with this chassis, but you have been chasing your tail. This may be one of those chassis that will be nearly impossible to fix via this forum . It sure would be nice to be able to lay eyeballs on this baby. Good luck.

Cliff, your comments about good spelling and vocabulary were well taken. "Nuff said.

Regards.

WC


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Post by Resistance is Futile on Sat Sep 29, 2012 3:14 am

I have tried to explain, doing one step at a time. You are right as to using a logical step by step approach. Thanks for your input. I have added a note about AVC action in my post following this one. But that is an issue for later if needed.
---------------------------
NOTE: It crossed my mind and I am thinking that there is a bad wires or connections even grid caps that have micro-fractured or cold soldered, (and yes even the tube socket connectors on the inside of the sockets). If this is the case then the wires or components will still make contact.

I have seen many clean solder connections but the wires under the solder were covered in grime and even dirt so the solder couldn't make the bond. I have seen many connectors that couldn't be wetted, because of impurities in wires or connectors. Kinda like wetting your hair but not cleaning out the oils in the hair. Your hair can look wet but its still not clean and still greasy.

Many steps have been done but not in order so it does make it rather difficult to assist in suggestions.

First off look for anything that doesn't look right. Make note of it even if you doubt that its a problem, such as bent wires, burned (discolored) wires or components, wires that are different in size or stranded VS solid, messy solder connections, loose and unconnected wires and components.
Make a check list and make a grid with letters and numbers in an map to locate each component. Check to make sure that the components and tubes are correct. Mark tube numbers on chassis locations

Smell for a burned smell, transformers especially, look for tubes that have red plates glowing or purple (Some rectifiers, voltage regulators and high powered tubes will do this.) Check for extremely hot components, this indicates shorts, tube however will get extremely hot, rectifiers and audio tubes especially, but not red plates.

Listen for abnormal sounds such as crackling, hissing indicating shorts and overloads.
Use your three senses in investigations.
Always use a dim bulb tester to turn a radio on the first time.
It helps if you have a list of test equipment and even include the model numbers. when requesting Help.

Always start with voltage checks, do step by step and list the readings, many schematics have those voltages listed either next to the component or in a chart, if not refer to tube chart data for expected voltages.
Trace each wire on a schematic and double check. Remember to be systematic.
So again visual, smells and sounds inspection first.
Then list results, then repair and replace obvious problems.
Then Voltage checks, then start doing troubleshoot by analysis, you must have your basic electronics and math theory down to do troubleshooting or you will fail each time.
Then you need to read about hints and kinks from manufactures when available, because of consistent problems that radio repairman have had.
And remember that most radios are not designed to have precise components and all will vary in quality because of price of manufacturing and changes not recorded. But most radios are designed to follow patents and a Westinghouse radio will be the same as an RCA or Hazeltine or Montgomery Wards radio. Components Values and tubes may be different but normally voltages will almost fall within the same range.


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Post by Resistance is Futile on Sat Sep 29, 2012 4:02 am

On the issue of AVC action

I am not that well versed in AVC, But tubes like the 6D6 were Tubes with variable gain were used in IF amp stages, so automatic volume control (AVC) could be done.
Tubes like 6K7, 6D6, 6SK7, and later 12SK7 were variable gain tubes. Usually called "remote cutoff" pentodes, as the tube wouldn't linearly cutoff current flow like a constant gain tube ("sharp cutoff") would. Yes, these remote cutoff tubes would not be usable in an audio amp, but these tubes lived in IF strips, where only a narrow bandwidth of frequencies were to be amplified, and harmonic distortion products fell outside the bandwidth of the output IF filter, and were thus ignored.

The audio detector tube would also measure the signal level, and thus could be fed back to the remote cutoff pentode IF tube. And also to any variable gain tubes at the front end of the radio. The audio detector diode was arranged to create more negative voltage for strong signals, and more negative voltage reduces the gain of the remote cutoff tubes.
this is taken from a web page and may help.
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Post by Resistance is Futile on Sat Sep 29, 2012 2:52 pm

Ben Delk wrote:Ok Cliff here's what I have so far.
[i]checked with meter all wires and resistors, point to point...ok
[i] test all caps with cap test unit, ...ok
[i] swapped tubed 80, 76, 6b5, no change

Going back over the schematic again I think I may have come across something I need to check again. Originally there was a double connection cap between the 76 tube pin2 (11Y=.03 mfd) and pin4 on the 6b5 tube. The second connection was 76 tube pin2 (11Z =.001 mfd) and the electrolytic cap (6Y=6mfd). These two may be reversed. I'll update you when I get a chance to recheck it later in the week.


Do you mean the caps are wired to the wrong components vs wrong polarity?
(if its a polarity I'm sure the radio wouldn't even play.) But again you need to be precise rather than generalities, not to say that you didn't replace. Forgive me but this is becoming a long posting and I may forget where you were.

Again try listing each step you have taken in some kind of numbered order, as that helps to sort things out that don't need addressing.
***Moving forward though***
Caps may check OK on a tester but still have High resistance leaks, does your cap check allow you to check in circuit or do you have to disconnect to test? Also remember that cap checkers don't check caps at RF frequencies normally only 60HZ or 1000Hz. So at lower frequencies they may pass muster but not at higher frequencies. So if one is on the edge of near questioning possibility of failure you wouldn't know, its best to replace old caps, Paper and electrolytics at least.
I would look at cap 11Y (0.03 mfd 400V) on the schematic it passes the signal from the detector to the grid of the audio tube 6B5 either its shorted and allowing DC to pass and making the grid of the audio tube positive which will shut off the tube or if its open then it blocks the audio signal, its only there to block DC not AC. Also zero in on cap 11Z (0.001 mfd 400V) as it may be open or shorted. Just a guess on my part in tracing backwards for loss of signal.
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Post by Ben Delk on Sun Sep 30, 2012 10:43 am

Thanks Cliff......... The caps have all been repalced and in the right placed and polarity. I say we just close this issue and I'll copy all these notes and put them in my file for further testing. At this point I can't see the forest for trees so I'm going to put this one back in a box, put it up on the shelf and hope at some point in the future the lights in my head will come on and maybe I can see what the heck is going on here. Again, Thank You for trying to help but at point I just need to step back from it and wait a bit.

Blessings and have a great day.

Ben
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Post by Wildcat445 on Sun Sep 30, 2012 11:37 am

Capacitors 11Y & 11Z were, apparently, part of a dual-cap assembly. 11 is an .03 used for coupling to the 6B5 and 11Z is an .001 used as plate by-pass. If they were reversed, the radio should not be dead. The complaint may be distorted/strangled/garbled audio, but not a dead speaker.

Okay. What do we know so far? The set has been recapped, resistors checked, and that, with a signal tracer, it has been found that music (audio, program) exists at some point in the chassis. But there is no output from the speaker. All the talk about frequency of caps, etc., is helpful information to someone perhaps more experienced in radio repair. But, Cliff, with all due respect, talking about frequency and its effect on caps in this case is like worrying about the turbocharger on a race car when this OP needs to learn to pedal his tricycle first! Let us attempt to steer him back to the basics and take this a LOGIGAL step at a time.

I am sure that, like everyone with a problem child on their service bench, that the OP has looked at this chassis ad nauseum. So let us, just for the sake of moving forward, assume for a moment that there are no miswires or other boo-boos obvious. Let us implement the old "cause and effect" style of diagnosis. We have been trying the "cause" part, without any concrete conlusions. Now let us try the "effect" side of things. We have an "effect" that is obvious. No sound from the speaker. Let's start with that.

The components up for test at this point are the speaker voice coil, the field coil, the secondary of the audio output transformer, the primary of the audio output transformer, the tone control switch, the power supply, and the 6B5 audio tube and its components, starting at the grid of the 6B5. Filter caps 6Y & 6Z are also in this, but, since we have signal somewhere in the radio, I am omitting them from the discussion at this time. We know from earlier testing that there is B+ on the plates of the 6B5. So that eliminates the power supply and the primary of the audio output transformer from suspicion. The field coil has been eliminated due to its involvement with B+. That leaves the output transformer secondary and the voice coil under suspicion. Substituting the speaker with a permanent magnet type will confirm whether the original unit is the problem. There is another possiblility that cannot be overlooked. The tone control switch. Its job is to bypass certain audio frequencies to ground. If it is shorted, it would not necessarily kill B+, but would possibly kill the audio.

It appears obvious to me that right now would be a good time to have a signal generator handy. I would recommend injecting a 400 cycle audio note into the grid of the 6B5 and check the entire audio section, from the grid of the 6B5 out to the speaker in one fell swoop. The schematic specifies 200 volts on the plate of the 6B5. It does not give different values for each plate. If memory serves, I remember reading that there is 280 volts on one plate and 240 on the other. Awfully high. Something like the 6B5 may not be conducting current. Line voltage and the impedence of the meter used will affect this some, but I would still consider this as a possible avenue of investigation, AFTER clearing the speaker of suspicion.

And just as an aside. Cliff, I do not believe that this chassis has AVC. Since the volume control effects the gain of the IF amplifier, is that not what AVC is supposed to do? That being the case, would not AVC in this chassis and the volume control work at cross purposes?

Well, Ben, it's your deal. The cards are in front of you. Either fold or raise. I don't know how to make this any simpler. After you try some of our suggestions, I will be happy to see what I can do to help should you need it. And good luck.

Ben, you posted a reply while I was doing mine. This is your radio, so you are free to do as you see fit. But my recommendation is to not give up just yet. You haven't learned anything, you have just frustrated yourself. If you are like me, this thing will haunt you until you fix it. We are all willing to do whtever we can to help you get to the bottom of it. And, in a self-serving vein, I am starting the restoration of a Crosley 170. The schematic is horrible and I can't read the component values. It has lots of the same components that you are working with. I am personally interested in your project. Whatever you decide to do, I understand.

Regards to all.

WC

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Post by Ben Delk on Sun Sep 30, 2012 2:52 pm

WC you are correct. My frustration with this project has reached a precipice and know everytime I walk by it I will have regret for not completing the job. I'm certain Cliff is feeling a little frustrated as well at not being able to get me steered in the right direction. Not his fault, just my lack of understanding of the whole process. I have the highest respect for anyone who knows how to do something and do it well. Ask me how a multi-segmented international network on different platforms is connected and that flows like buuuuter. I'll think about what you are saying but for the moment I need to take a few days to clear my head, collect my thoughts muster up the patience to start again.

Blessing to all and a double helping to those who try to help.
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Post by Wildcat445 on Sun Sep 30, 2012 3:13 pm

Ben, your understanding of computers puts this into more prospective. I hate computers and am an absoulte idiot when I work with one. This is why we have this forum. So that we can pool our collective strengths and help when we can. If it makes you feel any better, you are working on a radio that is far from conventional. I have had the schematic printed and laying in front of me for several days, and I see stuff every time I look at it that I had not noticed before. It may be a five tube radio and faily simple at first blush. But I can see where this circuit would cause me trouble, let alone somebody with less experience. And lest I come off as quite the expert, rest assured that I am not. There are lots of folks on here with more ability than I have. But I have been at this for awhile and like to figure out the tough cases. This is certainly one of those.

I have a procedure called "sun testing" that may work well for you in the short term. I push a chassis that I am having trouble with to the end of my bench where the sun shines in and let is stay there until I get the inspiration to work on it again. Maybe you need to "sun test" this chassis and then come back to it. I will certainly be happy to help in any small way I can.

Regards.

WC

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Post by Ben Delk on Sun Sep 30, 2012 3:22 pm

I like the process....thanks
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Post by Bill Cahill on Sun Sep 30, 2012 6:54 pm

May I inject something here?
First, try putting a pm speaker on secondary of output transformer, disconnecting one end of the old spkr voice coil first.
If the new spkr doesn't fix the problem do this. Get a couple of good, clear close up pictures of the ouput stage, and, connections to it, including that dual capacitor. Not the electrolytic, the other one.
It may be you have connected them incorrectly.
Bill Cahill

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Post by Ben Delk on Sun Sep 30, 2012 8:33 pm

Thanks Bill, I'll add that to my notes to try when I tackle it again. I'll be out of town most of this week and next weekend so I'm not sure I'll get a chance to check it before then. I truely appreciate You, Cliff and WildCat for all your suggestion and propting me to continue to try. I tell myself in a month, in a year in 10 years will this radio issue matter or define me. No, it is just a radio
and I will , at some point, master the skill to breath life back into it. I live to fight another day.
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Post by Ben Delk on Tue Oct 02, 2012 10:03 am

Headed to New Orleans early tomorrow on business so this will be a good opprtunity to read thru Alfred Corbin's Antique Radio Repair guide, yet one more time. It is a great book for beginner's, such as myself, and everytime I read thru it I see something that did not stand out before. My brian is like a dim bulb tester, when it is overloaded, it goes out. I'm sure when I get back next week I'll be ready to tackle the Crosley again.
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Post by Bill Cahill on Tue Oct 02, 2012 11:24 am

Good luck on your trip.....
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Post by Dr. Radio on Thu Oct 04, 2012 8:29 pm

Just a thought....there's been some excellent information presented within this thread, but maybe this might be helpful for someone in a similar situation, or for the future.

I believe this radio has a factory rear terminal board for phonograph input? I keep a junky battery operated Walkman to use for audio "injection". You could connect your audio source (always a good idea to use a capacitor like a .01 @ 600v in series with one of side of the audio out to prevent possible damage from stray raw DC) and feed the radio your own music in. This would at least split this radio in two, you'd know what things are working on the AF (audio) side, make sure that's working and then go about working on the RF/IF side (signal). Sort of a divide and conquer.

Just a thought. Shocked
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Post by Bill Cahill on Thu Oct 04, 2012 9:42 pm

Thanks for the excellent idea.... Great thought..............
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Post by Guest on Fri Oct 05, 2012 1:04 am

Sort of a divide and conquer.

I had an old Navy Chief for an instructor on radio repair and this is exactly how he taught us and exactly what he called it! Very Happy

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Post by Ben Delk on Thu Oct 11, 2012 10:30 am

Back home an ready to start on the beast again. I'll take all the suggestions and go down the list and see where it leads me. Update you later.
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