Well Guys I got this Falcon Radio table model I am working on no schamitic can not locate one ill look around for one.,
It seems the last person whom worked on it did not know what they were doing. I had to replace a carbon resistor it was burned out n broken ( See Pic ). It seems they double grounded the cap can on top of the case.(See Pic) Below
just thinking if this is really worth saving I think it is .

underside case label




Falcon Chassis



Replaced resistor (Red/Vio/Brn/ Silver % )
Old carbon was gold for a % I hope it will be ok this new way ?


Broken One

wiring looks fine. wax/paper capacitors should go. definitely that resistor needs a new one

To what tube, and to which pin, is that resistor connected?

If it is the cathode bypass cap for the audio stage, the value isn't particularly
critical, and a 20% tolerance part would probably work.

What is more important is why the resistor failed. That failure is usually
caused by a leaky grid coupling resistor that resulted in too much
current flowing through the tube.

I'd have no reservations about restoring that radio, it looks to be
in fairly decent shape.

Peter

The cap can is isolated from the chassis by the mounting insulator. They are using both negative lugs of the capacitor simply so the wires will fit, this is part of a B- bus for the set to reduce the shock hazard. You can follow this B- wiring around the chassis, it hopefully only connects to the actual chassis by a .01 MFD capacitor (approximately)
If the burned resistor connected to the 35Z5 rectifier pin 5 or 8, it probably acted as a fuse after the can capacitor shorted out.
Don

looks like the rectifier could be in the upper-left of the chassis next to what looks like the filter connected with 1.5Kohm resistor. definitely if the resistor in question smoked and not just failed open some high current somewhere it was connected to. high current could have been fixt with the now new capacitors while the resistor was just sitting there broken. otherwise very clean chassis. what does the case look like

well guys Thanks for the help I moved on to an Rca Victor Because at tis point in time i need to move on to much stress at this time with this radio. too hot to work even with a fan but in the evenings ill be working on an rca vistor bakelite radios I posted in this sec under toping wireing what to choose
again Thanks guys ever so much ill return to this at a later time asap i locaye a schamitic

I might question whether or not this is not a hot chassis radio. Not many made with octal tubes.

too hot in Mass ? no way

no its an old home so i guess no insolation I feel the heet LOL
But any way its our home and I love it here

I have seen worse, but it really is a clean chassis and yes the wiring could have and can be done to a better standard.

The caps with two sets of colours on them look like they could be Micamold & they are bad news. I would get rid of all of the paper caps & check, or replace those Micas mentioned. If the electrolytics get rid of them & do not forget to check resistors & short test the tubes.

That resistor was caused to fry. The question that needs a 100% correct answer is; "Why did it burn?" something overloaded it ... where is it in the scheme of things. Dropping, Cathode, Plate, wrong place (seen that done)

Marc

That .05 mfd cap that is between the 270 ohm resistor and the ground lugs of the filter cap would be on
the top of my culprit list.

On the sometimes you need to know: Otherwise, it's a paper cap., don't bother list.

If the equipment is available (I use an insulation tester @ 250V). I would measure it's resistance.

Marc

I have ordered the .05 caps needed this is why there still in place I am still dumbfounded by no schamitic ill have to look around this radiois ok. Nice radio but better with a schamitic.
But I have set it aside for now I have a few others to get ready for the show.

I would not stress over no circuit: But it would indeed be useful to know if everything is what it is suppossed to be and in the right place.

I have fixed several without a circuit, most of them follow a similar plot. With a bit of experience you can often tell just by looking, that something is not right.

Marc

Marc I totally agree a Radio someone has been in before is really diffcult with out a schamitic even not knowing the full before wireing ( Before someone changed it )and where everything was Orignally when was new is even tougher with out schamitic.

One bad one I had with no circuit, It was after appearing in Australias Silicon Chip Magazine, identified a 1930's Australian built EMMCO Autodyne Circa 1932. I found photo's of the chasses of several models but no circuit & the one that appeared in the Mag was mine, with appropriate warning as to its origin. As I reverse engineered it.

This had been monkeyed with & the output tube had been destroyed as the field coil was no longer there The circuits are virtually non existant. I considered a couple of other things "did not look right". I confirmed this with others with more technical background, in the Radio Club and by comparing it to other sets of the era.

I did also get an Australian built "Factory special" based on another model and sharing it's parts list and little else. Parts list was for both & there were several different.

Had to draw that one as well: It is believed to be a "one off" ... What a magnificent performer. Ist IF is a Bandpass filter.

One just has to be patient, with sets like that & take it a step at a time

Marc

when I was a kid back in the 70s Australia was giving land away to those who would come live in the country. although you had to serve two years in the military first. my brother and I were ready to go but he decided against it having just serving in the US Navy

Reading this thread, the consensus is that something caused that resistor to open up. From there the answers move on to "probably . . ." or "I think it's . . ." or "My guess would be . . .". Uh, MEASURE THE VOLTAGE! Even without service literature, you should be able to determine how much voltage is being dropped across that resistor. Then you can calculate the current, and the wattage. If the resistor is a half watt, the acceptable power should be no more than a quarter-watt, as the rule of thumb is to go at least double when determining what size to use. If out of tolerance, look for things that cann cause current flow. A leaky capacitor is indeed suspect; replace it and measure again. Don't button up the set until you're convinced that the voltage/current is what it should be.

A receiving tube manual can be very helpful when troubleshooting without a schematic. The tube basing diagram can identify all of the pins. This would allow you to sketch up your own partial schematic or compare to another similar set. There is an amazing similarity between AA5 sets. They can operate with fairly wide tolerances in component values. This chassis looks like a very good candidate for restoration. They don't come much simpler.

While replacing the capacitors go ahead and replace all the resistors too. Won't take much more time and won't cost all that much extra.