9th Oct 2018, 12:20 pm | #81 |
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Re: Aga Baltic AH37. Need help identifying old capacitor from 1930s radio
So far as I can make out from the photos and the OP's drawing, the switch for the 2nd RF transformer is connected to an HT feed, maybe the OP can confirm with a better photo showing the top of the 0.1uF,0.1uF,0.5uF capacitor block and the surrounding countryside so to speak?
It appears to have been modified around V2 as there is no grid bias for the gram input..... Lawrence. |
9th Oct 2018, 1:12 pm | #82 |
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Re: Aga Baltic AH37. Need help identifying old capacitor from 1930s radio
Could you try to explain to me in very simple terms how I could check to verify if the heaterwiring is the same in mine as the AH34? And btw; is heaterwiring something different that the wiring to the filament. It's all new to me so I still struggle with the terminology...
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9th Oct 2018, 1:29 pm | #83 |
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Re: Aga Baltic AH37. Need help identifying old capacitor from 1930s radio
The terms heater and filament are frequently interchanged.
I prefer to use the term heater for indirectly heated valves where a heater heats a separate cathode and filament for directly heated valves where the filament is also the cathode.
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9th Oct 2018, 2:10 pm | #84 |
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Re: Aga Baltic AH37. Need help identifying old capacitor from 1930s radio
The heater connections for the three amplifying valves are the same in your receiver as they are in the AH34, that's to say they are all connected in parallel across a common voltage source, that being one of the 4 volt secondary windings on the mains transformer.
The heater connections for the rectifier valve are connected across a separate voltage source, that being the other 4 volt winding on the mains transformer. In the AH34, the rectified HT from the rectifier is taken via a centre tap on its heater supply winding, in your drawing showing the rectifier the rectified HT is taken directly from one side of the rectifier's heater. If you're unsure about the meaning of parallel connections/circuits etc then take a look at this video, well worth watching: https://www.youtube.com/watch?v=UfZu5F4u7Ns Lawrence. |
9th Oct 2018, 3:08 pm | #85 |
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Re: Aga Baltic AH37. Need help identifying old capacitor from 1930s radio
Just altered the blueprint to make printing easier.
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9th Oct 2018, 3:27 pm | #86 |
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Re: Aga Baltic AH37. Need help identifying old capacitor from 1930s radio
George's diagram is looking good...just the reaction to sort out and I am not so sure about the 50K for cathode bias on V1.
The AL1 modification just needs to be changed by removing the 2x 700 and the electrolytic and wiring direct to chassis. The bias will need to be checked once the set is running as we don't know the HT voltage, the 500 ohms can be adjusted to suit. What we do need is some better pictures around V1 and the volume/reaction control so that last bit of the circuit can be finished. |
9th Oct 2018, 3:52 pm | #87 | |
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Re: Aga Baltic AH37. Need help identifying old capacitor from 1930s radio
Quote:
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9th Oct 2018, 4:04 pm | #88 |
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Re: Aga Baltic AH37. Need help identifying old capacitor from 1930s radio
A photo should show what's what, also more photos of the chassis underside and top side and from the front to show all the controls etc.
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9th Oct 2018, 4:38 pm | #89 |
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Re: Aga Baltic AH37. Need help identifying old capacitor from 1930s radio
I'll see if I can do that later tonight.
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9th Oct 2018, 7:21 pm | #90 |
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Re: Aga Baltic AH37. Need help identifying old capacitor from 1930s radio
Here are the first 5 in a series of photos. Will have to post multiple replies here to upload all of them. Here you can see the coil that is close to the largest capacitor block. You can also see the underside of the rectifier socket and the 4 wires that comes from the secondary of the PT to the rectifier. As you can see, it is one thick wire, and three equally thinner wires. If that can be of any help. More later.
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9th Oct 2018, 7:23 pm | #91 |
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Re: Aga Baltic AH37. Need help identifying old capacitor from 1930s radio
5 more photos.
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9th Oct 2018, 7:26 pm | #92 |
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Re: Aga Baltic AH37. Need help identifying old capacitor from 1930s radio
Even more..
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9th Oct 2018, 7:28 pm | #93 |
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Re: Aga Baltic AH37. Need help identifying old capacitor from 1930s radio
More coming in..
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9th Oct 2018, 7:30 pm | #94 |
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Re: Aga Baltic AH37. Need help identifying old capacitor from 1930s radio
A few more..
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9th Oct 2018, 7:33 pm | #95 |
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Re: Aga Baltic AH37. Need help identifying old capacitor from 1930s radio
Almost done...
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9th Oct 2018, 7:36 pm | #96 |
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Re: Aga Baltic AH37. Need help identifying old capacitor from 1930s radio
There!
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9th Oct 2018, 7:38 pm | #97 |
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Re: Aga Baltic AH37. Need help identifying old capacitor from 1930s radio
Excellent
Lawrence. |
9th Oct 2018, 8:04 pm | #98 |
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Re: Aga Baltic AH37. Need help identifying old capacitor from 1930s radio
The rectifier valve socket photos confirm that your drawing for the rectifier and HT take off point is correct.
Lawrence. |
9th Oct 2018, 8:12 pm | #99 |
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Re: Aga Baltic AH37. Need help identifying old capacitor from 1930s radio
Which in essence means it is not wired properly?
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9th Oct 2018, 8:46 pm | #100 |
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Re: Aga Baltic AH37. Need help identifying old capacitor from 1930s radio
So far as I can make out from the photos the base is wired correctly.
Lawrence. |