I picked up a Trirdyn a few days ago and have been going thru it to see what I need to make it work again. The megohm resistor is one I have never seen before; it has an adjustment pin in one end that goes in and out (like one of those cheap whistles they used to sell in dime stores). I checked it and there is no reading at all on meter, so I'm guessing it's open. Does anyone know what the value of the megohm resistor might be?
Thanks/Jeff
You have an adjustable grid leak resistor. Grid leak resistor values were from around 1 meg to 8 or 10 meg. Use a fixed 2.2 meg resistor. It will work.
http://www.nostalgiaair.org/PagesByModel/697/M0039697.pdf
Norm
:Merry Christmas All!
:
:I picked up a Trirdyn a few days ago and have been going thru it to see what I need to make it work again. The megohm resistor is one I have never seen before; it has an adjustment pin in one end that goes in and out (like one of those cheap whistles they used to sell in dime stores). I checked it and there is no reading at all on meter, so I'm guessing it's open. Does anyone know what the value of the megohm resistor might be?
:Thanks/Jeff
:
Thanks & Merry Chistmas.
Jeff
Hi Jeff
:
: You have an adjustable grid leak resistor. Grid leak resistor values were from around 1 meg to 8 or 10 meg. Use a fixed 2.2 meg resistor. It will work.
:
:http://www.nostalgiaair.org/PagesByModel/697/M0039697.pdf
:
:Norm
:
::Merry Christmas All!
::
::I picked up a Trirdyn a few days ago and have been going thru it to see what I need to make it work again. The megohm resistor is one I have never seen before; it has an adjustment pin in one end that goes in and out (like one of those cheap whistles they used to sell in dime stores). I checked it and there is no reading at all on meter, so I'm guessing it's open. Does anyone know what the value of the megohm resistor might be?
::Thanks/Jeff
::
:
:
C depends on B voltage being used on a tube. With these older tubes (01A) running up to 90 volts plate voltage, C is usually - 4 1/2. With higher voltage or other tubes different voltages may be required.
Norm
::If this is a tube with a wire that slides within, make sure that this is in fact an adjustable resistor and not an adjustable neutralizing capacitor.
::
:I assume it's a grid leak resistor. It's #16 on the schematic here (it is in parallel with a capacitor):
: http://www.crosleyradios.com/battery-sets/TRIRDYN-1.pdf
:Question: what's a good "C" voltage for this one, -4.5 or -6?
:Thanks//Jeff
:
thanks for your help//Jeff
:Hi
:
: C depends on B voltage being used on a tube. With these older tubes (01A) running up to 90 volts plate voltage, C is usually - 4 1/2. With higher voltage or other tubes different voltages may be required.
:
:Norm
:
:::If this is a tube with a wire that slides within, make sure that this is in fact an adjustable resistor and not an adjustable neutralizing capacitor.
:::
::I assume it's a grid leak resistor. It's #16 on the schematic here (it is in parallel with a capacitor):
:: http://www.crosleyradios.com/battery-sets/TRIRDYN-1.pdf
::Question: what's a good "C" voltage for this one, -4.5 or -6?
::Thanks//Jeff
::
:
:
When A- is bridged to C- a "C" battery isn't used. This was fairly common in older battery radios. It save on buying a "C" battery but the "B" battery has to supply more current.
The "C" battery biases grid negative. This causes the plate to draw less current.
Norm
:Norm,
:I noticed on the schematics that the A- and C- are bridged by a wire(?) at the terminals. Part of the wire still exists on my set, but it's been cut. Is this some kind of resistor wire, or just a connection between the two negative terminals? If it is some kind of resistor wire (I don't have any)should I remake the connection with a small value resistor?
:
:thanks for your help//Jeff
:
::Hi
::
:: C depends on B voltage being used on a tube. With these older tubes (01A) running up to 90 volts plate voltage, C is usually - 4 1/2. With higher voltage or other tubes different voltages may be required.
::
::Norm
::
::::If this is a tube with a wire that slides within, make sure that this is in fact an adjustable resistor and not an adjustable neutralizing capacitor.
::::
:::I assume it's a grid leak resistor. It's #16 on the schematic here (it is in parallel with a capacitor):
::: http://www.crosleyradios.com/battery-sets/TRIRDYN-1.pdf
:::Question: what's a good "C" voltage for this one, -4.5 or -6?
:::Thanks//Jeff
:::
::
::
:
:
That makes sense...I never would have thought of that.
Thanks//Jeff
:Hi Jeff
:
: When A- is bridged to C- a "C" battery isn't used. This was fairly common in older battery radios. It save on buying a "C" battery but the "B" battery has to supply more current.
:
: The "C" battery biases grid negative. This causes the plate to draw less current.
:
:Norm
:
::Norm,
::I noticed on the schematics that the A- and C- are bridged by a wire(?) at the terminals. Part of the wire still exists on my set, but it's been cut. Is this some kind of resistor wire, or just a connection between the two negative terminals? If it is some kind of resistor wire (I don't have any)should I remake the connection with a small value resistor?
::
::thanks for your help//Jeff
::
:::Hi
:::
::: C depends on B voltage being used on a tube. With these older tubes (01A) running up to 90 volts plate voltage, C is usually - 4 1/2. With higher voltage or other tubes different voltages may be required.
:::
:::Norm
:::
:::::If this is a tube with a wire that slides within, make sure that this is in fact an adjustable resistor and not an adjustable neutralizing capacitor.
:::::
::::I assume it's a grid leak resistor. It's #16 on the schematic here (it is in parallel with a capacitor):
:::: http://www.crosleyradios.com/battery-sets/TRIRDYN-1.pdf
::::Question: what's a good "C" voltage for this one, -4.5 or -6?
::::Thanks//Jeff
::::
:::
:::
::
::
:
:
Didn't see a cap connected to headphone jack?
http://www.nostalgiaair.org/PagesByModel/697/M0039697.pdf
One on this schematic is marked .002 mf. The other, across grid leak resistor, can be 250 pf.
If you put a cap across the headphone jack use a small value, .01 mf or less. This will filter out any remaining RF and limit high frequency audio response
Norm
::Does anyone know what value the two capacitors are in this set? The one that connects to the headphone jack is out.
:Thanks//Jeff
:
Thanks for the info. I was using the schematic at this site: http://www.crosleyradios.com/battery-sets/TRIRDYN-1.pdf
Turns out the cap was OK; I just didn't have my tester set low enough to measure it. The real problem was a broken wire in the feedback control. Once I fixed that the set pulled in all kinds of stations.
Jeff
Hi Jeff
:
: Didn't see a cap connected to headphone jack?
:
:http://www.nostalgiaair.org/PagesByModel/697/M0039697.pdf
:
: One on this schematic is marked .002 mf. The other, across grid leak resistor, can be 250 pf.
:
: If you put a cap across the headphone jack use a small value, .01 mf or less. This will filter out any remaining RF and limit high frequency audio response
:
:Norm
:
:
:
:::Does anyone know what value the two capacitors are in this set? The one that connects to the headphone jack is out.
::Thanks//Jeff
::
:
:
From my experience, that wasn't quite achieved, but they are very interesting sets. The cost savings would, of course, have appealed to Powell Crosley - the "mad-man Muntz" of his time.
Jeff
:By the way, I don't think it has been mentioned yet: one stage is used for BOTH RF and AF. Schematics for reflex circuits can make you go cross-eyed. The idea was that, say, a 4-tube set would perform like a 5-tube set.
:
:From my experience, that wasn't quite achieved, but they are very interesting sets. The cost savings would, of course, have appealed to Powell Crosley - the "mad-man Muntz" of his time.
:
The slogan, which was 3 tubes do the work of 5, was in Popular Science ads and even on emblems on some models of the radio themselves.
They enabled more people to buy radios at the time because of the lower cost, but radio was stil very much a luxury at the time ca. 1925.
:Amen to that! It's an interesting set, but it doesn't perform like my Freed-Eisemann NR7 or Grebe Syncrophase.
:
:Jeff
:
::By the way, I don't think it has been mentioned yet: one stage is used for BOTH RF and AF. Schematics for reflex circuits can make you go cross-eyed. The idea was that, say, a 4-tube set would perform like a 5-tube set.
::
::From my experience, that wasn't quite achieved, but they are very interesting sets. The cost savings would, of course, have appealed to Powell Crosley - the "mad-man Muntz" of his time.
::
: