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Thoughts on a McMurdo Silver Masterpiece VI Speaker
#37

I actually have a pair of Sovtek 5881 tubes...

but no, I think I'll get a pair of old ST-style 6L6G tubes for the McMurdo to keep that authentic "vintage" look. It's already going to have a modern speaker inside...no use in going overboard on modern stuff, I think.

Speaking of the speaker (heh heh, I made a funny Icon_lol - cymbal shot)...

Very productive day on the coaxial speaker project.

I disassembled it and reassembled, using threadlock this time on all of the screws.

I found that two of the four arms that attach to the woofer had the holes drilled in the wrong places - they were just a bit off, which was keeping the tweeter from being suspended flat as it should. A little work with my Ryobi "Dremel" tool and a special bit designed to enlarge holes in metal, elongating the two mounting holes, cured the trouble and the tweeter then attached to the woofer just fine, no problems.

I attached cloth-covered wire to both speakers for that "authentic" look, and a 4-pin Amphenol plug and cover on the end of the speaker cable.

I also used some large shrink tubing to hold the tweeter wires to one of the support arms:

[Image: http://www.philcoradio.com/images/phorum...0c5ab4.jpg]

[Image: http://www.philcoradio.com/images/phorum...e49b42.jpg]

Another view of the coaxial speaker, showing the speaker cable and Amphenol plug:

[Image: http://www.philcoradio.com/images/phorum...a174c5.jpg]

Next came mounting the speaker in the Clifton cabinet. I used two layers of stick-on speaker gasket material to ensure a good seal between speaker and cabinet. My cabinet had holes drilled around the speaker opening, but they were not spaced properly for this speaker. So I drilled four new holes and attached the speaker to the sounding board with four #8 wood screws.

[Image: http://www.philcoradio.com/images/phorum...da9d78.jpg]

No pedestal on this speaker, but it will have to do.

The speaker cable will plug into a project box I have yet to buy - this box will hold the 2-way crossover and the power resistor to take the place of the missing field coil. It will have an audio output transformer mounted on top. This box will have a cable running from it with a 5-pin plug; the 5-pin plug will plug into the speaker socket on the McMurdo amp.

[Image: http://www.philcoradio.com/images/phorum...295f94.jpg]

Slowly, it's coming together. Yes, it needs grille cloth; that is a problem for another day. When I begin electronic work on the set, I'll start a new thread.

Oh, in case you're wondering what happened to the Scott Philharmonic speaker that was sitting in this cabinet, it now resides inside my Allwave 23 Tasman which has a Philharmonic amp.

--
Ron Ramirez
Ferdinand IN


Messages In This Thread
RE: Thoughts on a McMurdo Silver Masterpiece VI Speaker - by Ron Ramirez - 03-02-2013, 04:43 PM



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