Chassis Plan printed out and adhered to aluminum sheets (old street sign)
via My 5E3 Build From Scratch incase you missed it....
Hey I'm going to follow
My 5E3 Build From Scratch
for my build. I want to salvage most of my parts.
Could someone tell me if I were to scrap this westinghouse floor radio
H-168 Ch= V-2118 Radio Westinghouse El. & Mfg. Co. - see als
would that take care of the trannys and some other parts including the wood.
the tubes needed for the 5e3 are not listed so I'm not sure if this would be a waste or not.
Couldn't view the schematic unless I joined RadioMuseum. I looked at an ebay auction for an H161 which looks similar. That radio has the OT mounted on the speaker, couldn't read the tube chart. I'm not in favor of destroying the radio to build a guitar amp. The power amp in that radio is probably not more than 5 watts. What tubes does your radio use?
WARNING! Musical Instrument amplifiers contain lethal voltages and can retain them even when unplugged. Refer service to qualified personel.
it lists the valves under the picture but I have already passed on that idea. It was a local craigslist ad, went and looked at it and the wood was veneer anyways so I'm bidding on a auction for an old 6v6 amp.
I'm confused on how to determine what Ohm speaker to use with this transformer that came with my parts amp. How do you tell?
Last edited by ernest; 02-03-2012 at 01:46 AM.
The chassis I'm using parts from comes from an old Ampro Projector. I can find old schematics for Ampro Projectors but none so far that list 2-6v6, 1-5y3, and 12ax7.
a google search on ampro projector images turns up the specs for a model Stylist 16.
Ampro Stylist 16
another stylist 16 manual with schematic
Lists two 6v6 tubes but a cant find any info of speaker
The only reference to speaker I can find is 8 ohm in these manuals....is that my answer?
Finding Unknown Values for Output Transformers
The other thing I would want to be sure about is: do I have a single ended or a push pull transformer? Pretty sure you have a push pull, but SE OTs with parallel output tubes are not unknown.
Hope this points you a bit in the right direction.
He just means, put a small AC voltage into the secondary winding... measure across the full primary winding ... divide the small number into the big number... take that new number and square it...
Then multiply that sq'd number by the speaker load impedance (4 ohm, 8ohm etc) and you have the primary impedance.
6vac into the secondary wires... measure the primary wires at say 180vac. Oh and that will knock you on your ass.
180v divided by 6v = 30 a 30:1 voltage ratio
30^2 or 30x30 = 900
900 x 8 ohm speaker = 7200 ohms
900 x 4 ohm speaker = 3600 ohms
without a doubt he confirmed that his which looks damned identical, came with a 16 ohm speaker.
so, decided on a speaker. I didn't have a lot to spend on a speaker at least not right now. I've already given a big chunk to the resistors, caps, knobs, jacks, etc....so I had to save on the speaker...for now.
so many options, AlNico/ceramic, watt, ohm, so I would love to have a celestion blue, tone tubby, or something like that, I almost went with an old organ speaker with square alnico mag. What I ended up with was very affordable, a celestion G12 that has a modified aluminum voice coil and Hemp cone. I like a bass and mid with early breakup so I hope I'll be happy with it.
and a oxblood grill.
This chassis is kickin my ass. blew a hole through it with a welder so I'm going to have to make some sides and pop rivet them instead.
Hmm .. the eyelet circuit board appears to have the B+ rail grounded side on the wrong side of the board with respect to the chassis...
Doug might be doing that on purpose for some reason... other then just to be different (guess that's OK) I don't know why.
that and I'm using old trannys with extra wires that I don't know what to do with. for instance I have six wires coming out of my output tranny, yet I can only find three on all the schematics.
Still trying to figure out where I star ground all of this as well. just pick a bolt on the chassis and connect all my grounds to it?
two unaccounted wires on the PT as well, a brown one and a bare wire?
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