Forums :: Resources :: Features :: Photo Gallery :: Vintage Radio Shows :: Archives
Support This Site: Contributors :: Advertise


It is currently Jul Wed 15, 2020 9:36 am


All times are UTC [ DST ]





Post New Topic Post Reply  [ 140 posts ]  Go to page Previous  1 ... 3, 4, 5, 6, 7  Next
Author Message
 Post subject: Re: Radiola Grande Restoration
PostPosted: Apr Sat 18, 2020 5:18 pm 
Member

Joined: May Sat 30, 2015 11:49 pm
Posts: 1206
Location: Keystone Heights, FL, USA 32656
More specifically, the grids of all 3 audio tubes should be -3.98v. Somehow the 1st audio tube grid is connected to 48 volts, according to your measurements.

Maybe this will help. Photo courtesy of Radiomuseum.org.
Attachment:
RGxfrmers.jpeg
RGxfrmers.jpeg [ 213.2 KiB | Viewed 459 times ]

_________________
Jeff
“Nothin’s worth nothin ‘till somebody wants it.”—Irv Metter


Top
 Profile  
 
 Post subject: Re: Radiola Grande Restoration
PostPosted: Apr Sat 18, 2020 9:12 pm 
Member
User avatar

Joined: Sep Mon 18, 2017 2:23 am
Posts: 5542
Location: Plymouth, MI
I'm getting 90v at the #1 connection of the H transformer where you have it marked 45v, meter negative lead connected to B- on the ARBE. All other connections check the same as you have marked them.

_________________
Dan

Museum Curator
https://roaringtwentiesantiqueradiomuseum.com/


Top
 Profile  
 
 Post subject: Re: Radiola Grande Restoration
PostPosted: Apr Sat 18, 2020 11:22 pm 
Member
User avatar

Joined: Jan Thu 01, 1970 1:00 am
Posts: 14330
Location: S. Dartmouth MA 02748-1225 USA
Attachment:
Radiola Grand Schematic.jpg
Radiola Grand Schematic.jpg [ 167.05 KiB | Viewed 453 times ]

Could there be some confusion in the re-assignment of B voltages to the multiple (unused) A+ connections. Since an internal "B" battery is not in use?

Chas

_________________
List' & I will Enchant Thine Ear


Top
 Profile  
 
 Post subject: Re: Radiola Grande Restoration
PostPosted: Apr Sat 18, 2020 11:37 pm 
Member

Joined: May Sat 30, 2015 11:49 pm
Posts: 1206
Location: Keystone Heights, FL, USA 32656
Can you post a photo of that area? Zoom out so all 4 tube sockets can be seen.

Do you have B- connected to A- at the arbe? That may be a mistake on my part

I am confused as to how there can be 90v on terminal 1 of H and 45v on terminal 2. Should be the same voltage at both terminals.

Yesterday you said audio tube 1 had 48 volts on grid pin; today it is C- (3.9v)?

_________________
Jeff
“Nothin’s worth nothin ‘till somebody wants it.”—Irv Metter


Top
 Profile  
 
 Post subject: Re: Radiola Grande Restoration
PostPosted: Apr Sun 19, 2020 12:51 am 
Member
User avatar

Joined: Sep Mon 18, 2017 2:23 am
Posts: 5542
Location: Plymouth, MI
Attachment:
SAM_2241.JPG
SAM_2241.JPG [ 692.32 KiB | Viewed 452 times ]

_________________
Dan

Museum Curator
https://roaringtwentiesantiqueradiomuseum.com/


Top
 Profile  
 
 Post subject: Re: Radiola Grande Restoration
PostPosted: Apr Sun 19, 2020 12:59 am 
Member
User avatar

Joined: Sep Mon 18, 2017 2:23 am
Posts: 5542
Location: Plymouth, MI
B- and A- are not connected at the ARBE.


atwaterkent1 wrote:
Attachment:
SAM_2241.JPG

_________________
Dan

Museum Curator
https://roaringtwentiesantiqueradiomuseum.com/


Top
 Profile  
 
 Post subject: Re: Radiola Grande Restoration
PostPosted: Apr Sun 19, 2020 1:07 am 
Member
User avatar

Joined: Jan Thu 01, 1970 1:00 am
Posts: 14330
Location: S. Dartmouth MA 02748-1225 USA
atwaterkent1 wrote:
B- and A- are not connected at the ARBE.
atwaterkent1 wrote:
Attachment:
SAM_2241.JPG
Because, if true to the schematic, that connection is accomplished in the radio...

So where is the 45 volts going if it is not to the detector B+, accidentally to the C- connections?

If true, what has become of the C- connected to the +90 for the first AF? But that is common to the PP output. Oh my?

Chas

_________________
List' & I will Enchant Thine Ear


Top
 Profile  
 
 Post subject: Re: Radiola Grande Restoration
PostPosted: Apr Sun 19, 2020 2:36 am 
Member
User avatar

Joined: Sep Mon 18, 2017 2:23 am
Posts: 5542
Location: Plymouth, MI
Chas was right and I stupidly missed it. Heyboer rewound H transformer with leads in different places. Okay, I'm an idiot. I can get a weak but clear signal through the regular headphone jack now and can tune different stations. Amp section still not working. Transformer voltages on the two transformers Jeff marked in photo are correct. Current tube voltages as shown....

Attachment:
Radiola Grand Tube Voltages.jpg
Radiola Grand Tube Voltages.jpg [ 384.05 KiB | Viewed 447 times ]



New photo with H transformer connections corrected.....

Attachment:
SAM_2245.JPG
SAM_2245.JPG [ 754.03 KiB | Viewed 447 times ]

_________________
Dan

Museum Curator
https://roaringtwentiesantiqueradiomuseum.com/


Top
 Profile  
 
 Post subject: Re: Radiola Grande Restoration
PostPosted: Apr Sun 19, 2020 2:32 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 2847
Location: Massachusetts
Does it work now?


Top
 Profile  
 
 Post subject: Re: Radiola Grande Restoration
PostPosted: Apr Sun 19, 2020 3:39 pm 
Member
User avatar

Joined: Sep Mon 18, 2017 2:23 am
Posts: 5542
Location: Plymouth, MI
MRX- As I wrote in my post, the amp section still isn't working. No sound from speaker and very weak sound from headphones.

_________________
Dan

Museum Curator
https://roaringtwentiesantiqueradiomuseum.com/


Top
 Profile  
 
 Post subject: Re: Radiola Grande Restoration
PostPosted: Apr Sun 19, 2020 4:06 pm 
Member

Joined: May Sat 30, 2015 11:49 pm
Posts: 1206
Location: Keystone Heights, FL, USA 32656
Now, try it as a 2 tube radio. Disconnect 2 from the K transformer and connect phones between disconnected wire and 4 on K transformer.

_________________
Jeff
“Nothin’s worth nothin ‘till somebody wants it.”—Irv Metter


Top
 Profile  
 
 Post subject: Re: Radiola Grande Restoration
PostPosted: Apr Mon 20, 2020 12:32 am 
Member
User avatar

Joined: Sep Mon 18, 2017 2:23 am
Posts: 5542
Location: Plymouth, MI
Nothing Jeff.

_________________
Dan

Museum Curator
https://roaringtwentiesantiqueradiomuseum.com/


Top
 Profile  
 
 Post subject: Re: Radiola Grande Restoration
PostPosted: Apr Mon 20, 2020 2:45 am 
Member
User avatar

Joined: Jan Thu 01, 1970 1:00 am
Posts: 14330
Location: S. Dartmouth MA 02748-1225 USA
"nothing"...

Not good, placing the 'phones in series with the output winding of the 1st audio output and with the voltages given, means there is a problem other the tuner is not regenerating enough to have any kind of signal.

A "live" audio can be inserted by making up a voltage divider for the audio output of the RF generator, remember there is no attenuator. Select any 1K resistor and any 10k resistor and solder them in series add a .01/630 volt at that junction. Connect the 1k resistor free end to the ground of the audio output take a ground lead from their too. Connect the 10k resistor to the high or other jack of the audio output. Add an extension lad to the cap and put a probe on it. Take the ground wire from the audio and connect that to A+

Note I want to use A+ as the instrument ground not B- keep that in mind.

Turn on the generator and be sure controls are set to generate an audio signal. Test by putting the audio signal on the Baldies, they should whine at 1khz. if not find out why.

Reconnect the B+ to that transformer, power the set and turn up the filaments. now touch the cap probe to the plate of tube #2, there should be a loud whine in the speaker...

What you have made is an audio signal injector, the detector is the radios speaker.

Probe terminal one or terminal 5 of transformer "L" or the plates of tube 4 and tube 3. You should get equal volume tone from each...

Now probe the grids of tube 4 and 3, equal but louder volume.

Now probe terminal 4 of transformer "K" or the plate of tube 2, the volume should be even louder.

If there has not been a progressive increase in tone loudness then there is a flip in one or both the transformer windings that have two leads joined.

It will take AC voltmeter measurements or the two channel scope to determine, first if transformer "K" is flipped and a reverse tone injection technique to determine if transformer "L" is flipped. Using the tone as the AC source.

Your capacitor probe is safe will not pass DC but will store a tiny charge when used to touch a B+ connections. It could nip if you get into contact.

Chas

_________________
List' & I will Enchant Thine Ear


Top
 Profile  
 
 Post subject: Re: Radiola Grande Restoration
PostPosted: Apr Mon 20, 2020 6:08 pm 
Member

Joined: May Sat 30, 2015 11:49 pm
Posts: 1206
Location: Keystone Heights, FL, USA 32656
atwaterkent1 wrote:
Nothing Jeff.


Try Chas' test. Also, refer to page 4 and see if it still works as a 1 tube radio.

Looking at your photo, the H transformer is numbered (from the top) 4,2,1,3. 2 and 1 should be the primary; 4 and 3 should be the secondary. What is the resistance, 2 to 1 and 4 to 3?

Are the 2 large black wires in the foreground of your photo the "C" battery connections?

_________________
Jeff
“Nothin’s worth nothin ‘till somebody wants it.”—Irv Metter


Top
 Profile  
 
 Post subject: Re: Radiola Grande Restoration
PostPosted: Apr Tue 21, 2020 2:03 am 
Member
User avatar

Joined: Sep Mon 18, 2017 2:23 am
Posts: 5542
Location: Plymouth, MI
Didn't get much time to work on radio today. Busy day and got a new radio in and wanted to check it out to let the seller know everything is ok.

On H transformer:

3 + 4 = 1.964k ohms
1 + 2 = .485k ohms

Wires in foreground are C power connections.

Tried the one tube radio test, got nothing until I disconnected the +90v, then it worked. I think I'll go to Costco and get the one gallon bottle of aspirin. :lol:

I should have more time to do the other stuff tomorrow, still recovering from last Monday.

_________________
Dan

Museum Curator
https://roaringtwentiesantiqueradiomuseum.com/


Last edited by atwaterkent1 on Apr Tue 21, 2020 3:57 am, edited 1 time in total.

Top
 Profile  
 
 Post subject: Re: Radiola Grande Restoration
PostPosted: Apr Tue 21, 2020 3:49 am 
Member
User avatar

Joined: Jan Thu 01, 1970 1:00 am
Posts: 14330
Location: S. Dartmouth MA 02748-1225 USA
Quote:
On K transformer:
3 + 4 = 1.964k ohms
1 + 2 = .485k ohms

Umm, why are readings taken across the windings? If this is a leakage test, failed miserably...

Check the navigation of the transformer markings and actual connections. Do the actual connections conform to the schematic, wire for wire, label for label?

Oh, these are DVM readings?

Chas

_________________
List' & I will Enchant Thine Ear


Last edited by Chas on Apr Tue 21, 2020 6:12 pm, edited 2 times in total.

Top
 Profile  
 
 Post subject: Re: Radiola Grande Restoration
PostPosted: Apr Tue 21, 2020 3:56 am 
Member
User avatar

Joined: Sep Mon 18, 2017 2:23 am
Posts: 5542
Location: Plymouth, MI
Sorry Chas, H transformer.

_________________
Dan

Museum Curator
https://roaringtwentiesantiqueradiomuseum.com/


Top
 Profile  
 
 Post subject: Re: Radiola Grande Restoration
PostPosted: Apr Tue 21, 2020 11:10 pm 
Member

Joined: May Sat 30, 2015 11:49 pm
Posts: 1206
Location: Keystone Heights, FL, USA 32656
atwaterkent1 wrote:

On H transformer:

3 + 4 = 1.964k ohms
1 + 2 = .485k ohms

Wires in foreground are C power connections.

Tried the one tube radio test, got nothing until I disconnected the +90v, then it worked.

Transformer numbers are good.

On one tube test, did you do it exactly as before? That is, disconnect wire to H2 and connect phones to that wire and H1? I don’t see how the 90 volts connected or disconnected would have any effect. If you did not disconnect anything, just clipped in the phones to H2 and H1 then somehow the 90 volts is getting into the 45 volt circuit.

_________________
Jeff
“Nothin’s worth nothin ‘till somebody wants it.”—Irv Metter


Top
 Profile  
 
 Post subject: Re: Radiola Grande Restoration
PostPosted: Apr Tue 21, 2020 11:25 pm 
Member
User avatar

Joined: Sep Mon 18, 2017 2:23 am
Posts: 5542
Location: Plymouth, MI
I had the C voltage on. I just tested it again with the 90v connected and the C voltage off and it works great as a one tube. When I turn on the C voltage the signal cuts out. With the C voltage on and the 90v disconnected, it works again. :?

_________________
Dan

Museum Curator
https://roaringtwentiesantiqueradiomuseum.com/


Top
 Profile  
 
 Post subject: Re: Radiola Grande Restoration
PostPosted: Apr Tue 21, 2020 11:41 pm 
Member
User avatar

Joined: Sep Mon 18, 2017 2:23 am
Posts: 5542
Location: Plymouth, MI
Chas wrote:
"nothing"...

Not good, placing the 'phones in series with the output winding of the 1st audio output and with the voltages given, means there is a problem other the tuner is not regenerating enough to have any kind of signal.

A "live" audio can be inserted by making up a voltage divider for the audio output of the RF generator, remember there is no attenuator. Select any 1K resistor and any 10k resistor and solder them in series add a .01/630 volt at that junction. Connect the 1k resistor free end to the ground of the audio output take a ground lead from their too. Connect the 10k resistor to the high or other jack of the audio output. Add an extension lad to the cap and put a probe on it. Take the ground wire from the audio and connect that to A+

Note I want to use A+ as the instrument ground not B- keep that in mind.

Turn on the generator and be sure controls are set to generate an audio signal. Test by putting the audio signal on the Baldies, they should whine at 1khz. if not find out why.

Reconnect the B+ to that transformer, power the set and turn up the filaments. now touch the cap probe to the plate of tube #2, there should be a loud whine in the speaker...

What you have made is an audio signal injector, the detector is the radios speaker.

Probe terminal one or terminal 5 of transformer "L" or the plates of tube 4 and tube 3. You should get equal volume tone from each...

Now probe the grids of tube 4 and 3, equal but louder volume.

Now probe terminal 4 of transformer "K" or the plate of tube 2, the volume should be even louder.

If there has not been a progressive increase in tone loudness then there is a flip in one or both the transformer windings that have two leads joined.

It will take AC voltmeter measurements or the two channel scope to determine, first if transformer "K" is flipped and a reverse tone injection technique to determine if transformer "L" is flipped. Using the tone as the AC source.

Your capacitor probe is safe will not pass DC but will store a tiny charge when used to touch a B+ connections. It could nip if you get into contact.

Chas


One end of each resistor and both ends of the cap all soldered together?

_________________
Dan

Museum Curator
https://roaringtwentiesantiqueradiomuseum.com/


Top
 Profile  
 
Post New Topic Post Reply  [ 140 posts ]  Moderators: Marcc, Norm Leal Go to page Previous  1 ... 3, 4, 5, 6, 7  Next

All times are UTC [ DST ]


Who is online

Users browsing this forum: No registered users and 18 guests



Search for:
Jump to:  


































-->


Privacy Policy :: Powered by phpBB