[Boatanchors] Looking for Help: Magnavox AC 2
w_b_morton at hotmail.com
Sun Dec 15 11:23:13 EST 2013
First, I will apologize ahead of time if this is a bit out of the Boatanchor realm...
I came upon a very pretty Magnavox AC 2 amplifier yesterday. The unit is really quite nice physically and the original decal on the front is beautiful. I would like it to do more than just collect dust so there is now another project staring me in the face. I am looking for the following items as various web searches have not been very successful thus far.
1. A schematic. There was a hand-drawn schematic inside the box, but a verified one would be great. There is one loose wire from the internal transformer and I think I know where it goes...I think.
2. A transformer for the input side. I found a PDF file of the operating instructions for both the AC 2 and AC 3 models and it mentions the need for an 'any standard amplifying transformer' on the input side. This transformer would connect between the phones output of a radio/crystal set and the input terminals of the AC 2. I thought I had one some time back, but I am now worried that I gave it away or it has been lost to history.
3. Any suggestions for the type of tube I should use. It came with CX-301A tubes, but the spec sheets I have read say this tube is not the best for power amplification. I may use these for initial trials. Unfortunately the instruction PDF I have just mentions 'any standard transmitting tubes may be used, with from 250 to 500 volts on their plates...'
4. The output of the AC 2 has connections for both the field and signal for a field coil speaker. I am wondering if I can use, say, a universal output transformer to drive a modern speaker instead. Again, the PDF file is lacking on technical details. It does show the use of Magnavox Reproducer R-2 or R-3 but I do not have those and it is not my intent to re-create a living room from 1929.
I believe I can rig up a reasonable set of power supplies. The 5 volt filaments should be easy...maybe even use the 5V output from a surplus PC power supply. I expect the B+ requirements for whatever tubes I need would require relatively low currents, so I should be able to put something together myself or find something on Craigslist, etc.
Thank you all very much in advance for whatever helpful advice (or parts) you may have. Again, my apologies if this is too far off outside the intent of the Boatanchor community.
Best Regards and Happy Holidays,
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