My new project

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Re: My new project

Post by frank1956 on Mon Nov 03, 2014 12:23 am

Dr. Radio,
So how should I proceed in connecting  pin # 2 to the B-? I have several idea, but not sure if any of them are correct.

Can I run a wire from where the yellow wire connect to the volume control coming off pin #2? Or just move the yellow wire coming of pin #2 to where the B- is connected to the volume control side??

When you say "You need to correct the mis-wire, not just jumper the circuit as is to a B- connection or that will cause more grief". What do you mean? Not to jump the two pin's together i.e. connecting pin #2 to pin # 5??

Frank
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Re: My new project

Post by frank1956 on Mon Nov 03, 2014 11:56 am

Dr. Radio,
After a little more investigation I can confirm pin #2 12AT6 does connected to B-, through yellow wire vie black wire to B-. If you look at the previous picture I posted, it the black wire running under the .03 capacitor across the volume control. I have attached a video of the sound I am getting from the speaker.

http://illiweb.com/fa/pbucket.gif?sort=3&o=0


Frank
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Re: My new project

Post by frank1956 on Mon Nov 03, 2014 6:35 pm

I was double checking things on this radio and notice this, not sure if anything connects to this or not???






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Re: My new project

Post by 75X11 on Mon Nov 03, 2014 6:48 pm

That looks like someone soldered 2 unused lugs to the chassis to mount that choke. Never seen such an installation.
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Re: My new project

Post by Dr. Radio on Mon Nov 03, 2014 8:57 pm

frank1956 wrote:I was double checking things on this radio and notice this, not sure if anything connects to this or not???






Frank



Frank,

That's factory. That's how Crosley mounted the oscillator coil to the chassis apron. They simply soldered the unused lugs through.
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Re: My new project

Post by Dr. Radio on Mon Nov 03, 2014 9:09 pm


Watched your video. Sounds like the amp *may* be working, but it has "no" input. Was the video with the antenna connected?

May not have mattered. If you're getting the loud HUUMMMM with the center of the volume control touched, the amp *should* be working.

I'm thinking what the next step should be..... (Others welcome to jump in Smile )


Voltages reading close to schematic?

That may get us closer.

Next might be to inject audio (if your signal generator provides audio output alone) and double check the amp circuitry.

We really need to know if the amp section is a-ok first, in order to proceed as the next step is to work back towards the antenna then to see if RF circuitry is a-ok and hopefully the IF transformers aren't ka-poot preventing signal from passing thru the stages. That would be a worst case scenario. But we ain't there yet. Very Happy

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Re: My new project

Post by frank1956 on Mon Nov 03, 2014 9:28 pm

Dr. Radio,
No the antenna was not connected. My EICO 324 does have audio output. All voltage reading are close to the  schematic with the exception of  pn's #5 & #6 tube 50B5. Pin # 5 152 (schematic 110) #6 107 (schematic 85). Though are the only two that higher then normal voltage reading, every other pin voltage are good or within tolerance.

Frank
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Re: My new project

Post by 75X11 on Mon Nov 03, 2014 9:47 pm

I'm wondering if there is any response to applied rf at each stage. It seems that there is, as the Dr. pointed out, no signal being applied to the audio section. If it is there through the rf and if sections, where is it being lost? Or is there even an lo or if signal to be possibly lost between stages?
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Re: My new project

Post by 75X11 on Mon Nov 03, 2014 10:03 pm

The Dr. is right to inject an audio signal at or after the volume control to make sure the audio section is capable of processing audio. If it does then look at the rf/if sections.
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Re: My new project

Post by frank1956 on Mon Nov 03, 2014 10:52 pm

75, correct me if I am wrong, but to injected an audio signal that would start on the 12BA6 pin #5 correct?

I personally now that I have had time to inspect this radio a little bit more, believe the volume control is shot. The reason I say this and the reason I ask the question in a previous post in this thread is I have notice on several occasion I have turned the radio on and get nothing??? (no power). Once I mess with the volume control switch for about a minute or so and have had to spay contact spray inside the volume control will it make contact to power the radio up. I have also notice a kinda of squeaky sound as I turn the volume control knob. So with these few observation would this be a good candidate for a bad switch?? When I picked this radio up it was really in sad shape, mostly the interior i.e. some paper cap were completely melted or blowed out. I am sure that these is not the only problem with this radio!!!

I plan on removing it to look inside to see if it is something that can be fixed or just replace it. Any suggestion on where I might find one and what do I need to ask for??

Frank
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Re: My new project

Post by 75X11 on Mon Nov 03, 2014 11:52 pm

Try a audio signal at pin 7 of your 50B5. You should even get some scratching just touching it with the blade of a small insulated screwdriver. To definitely check your volume pot, disconnect 2 of the lugs from the circuit. measure across the 2 outer lugs to obtain the total resistance of the pot. Then put 1 lead on 1 outer lug and1 on the center and move the control throughout its' range. You should see a very low resistance to near the full amount you read across both outer lugs. If you get an open across the 2 outer lugs it is very likely it s bad. Use your analog meter on the outer to center test so you can see if there are any high resistance spots as you adjust the pot. If you get the total resistance across the outer lugs and a smooth increase and decrease outer to center, it should be good.
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Re: My new project

Post by frank1956 on Tue Nov 04, 2014 10:57 am

75X11 wrote:Try a audio signal at pin 7 of your 50B5.   You should even get some scratching just touching it with the blade of a small insulated screwdriver.  To definitely check your volume pot, disconnect 2 of the lugs from the circuit.  measure across the 2 outer lugs to obtain the total resistance of the pot.  Then put 1 lead on 1 outer lug and1 on the center and move the control throughout its' range.  You should see a very low resistance to near the full amount you read across both outer lugs.  If you get an open across the 2 outer lugs it is very likely it s bad.  Use your  analog meter on the outer to center test so you can see if there are any high resistance spots as you adjust the pot.  If you get the total resistance across the outer lugs and a smooth increase and decrease outer to center, it should be good.


75, Does it matter which two lugs I disconnect?  This has 5 lugs (three on the top and two on the back). One has strictly B+ and the other one has B- and a few other cap's resistor's connected.

Frank
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Re: My new project

Post by 75X11 on Tue Nov 04, 2014 11:12 am

The volume pot probably has a power switch piggybacked on the back. The power switch will have the two lugs. Leave them alone. You are concerned with the pot(entiometer) that has 3 lugs. remove the center and 1 outside lug and go through the test I already described. Leave the unit unplugged throughout this.
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Re: My new project

Post by frank1956 on Tue Nov 04, 2014 11:24 am

Thanks
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Re: My new project

Post by frank1956 on Tue Nov 04, 2014 12:31 pm

75, I forgot to ask what type of measurements am I taking on the analog meter i.e. ohms? Also tried the insulated screwdriver on pin #7 50B5 an nothing.
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Re: My new project

Post by 75X11 on Tue Nov 04, 2014 1:30 pm

Check your schematic and parts list. It appears to be 1 megohm.
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Re: My new project

Post by frank1956 on Tue Nov 04, 2014 1:47 pm

I did and that is it. Took ohms resistance reading (100 X on analog meter) on both outer lug's and again on outer lug and center lug, got no reading. The only time I got a reading was when the volume control switch was just about in the off/on position (a hairline from being either on or off no reading in between), this was true for both test. I assume volume control switch is BAD!!!!


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Re: My new project

Post by Wildcat445 on Tue Nov 04, 2014 1:49 pm

I was posting when Frank was.  Sorry for the intrusion.  He answered my question.

Frank, if you were on the 100X scale on your meter, one megohm (1 million ohms) would give you an infinite reading, since the reading was too "big" for your meter.  Try it on either the 10K times setting or something like that.  On the 10K setting of your meter, you should read 100 at least if the control is good.  You should try again on a higher meter setting before you condemn that control.

WC

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Re: My new project

Post by frank1956 on Tue Nov 04, 2014 2:08 pm

WC, Same results as with 100X. Only time reading happen was when switch was either just about on or off, again nothing in between.

Frank
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Re: My new project

Post by 75X11 on Tue Nov 04, 2014 4:40 pm

Now, when you say you got a reading was when the switch was either just about off or on, was that from the end to center? and just to confirm did you get nothing between the two outer lugs?
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Re: My new project

Post by frank1956 on Tue Nov 04, 2014 4:50 pm

Got noting from outer to outer and nothing from outer to center. Both had reading as stated just before on or off.

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Re: My new project

Post by 75X11 on Tue Nov 04, 2014 4:55 pm

That sounds like you have a break at the end of the pot where the wiper is when the switch is engaged.  There is a 1 megohm pot listed on this page.  Look at the pdf sheet that accompanies it and see if replacing tour pot portion of that assembly is something you would want to try.

http://www.surplussales.com/Potentiometers/TVRadio/TVRadio-1.html
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Re: My new project

Post by frank1956 on Tue Nov 04, 2014 8:54 pm

Thanks. I will take a look at it.


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Re: My new project

Post by Wildcat445 on Tue Nov 04, 2014 11:19 pm

I was not trying to insult your intelligence, Frank. I didn't want you to replace the volume control and have that not fix it. Good luck.

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Re: My new project

Post by frank1956 on Wed Nov 05, 2014 12:23 am

WC,
Not at all. Glad to get your input, I am sure the volume control is some of the problem, but problem not the cure.

Frank
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Re: My new project

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