electron tube

4

Hey everyone!

Here are the final pictures of the Graetz Melodia radio. The owner has it in his possession now, so the project is officially done and closed. This has been a long one… over a year of working on it (on and off).

I learned a lot during this project and had a lot of fun bringing this beautiful radio back to life.

Next up… continue on with the Philco 39-45, and possibly work on one of my own personal radio projects (Gasp!).

Anyway… thanks for following along with this one and until next time…

Stay tuned!

Me (An Astronomy Nerd) in Astrophysics...

Teacher: *showing us emission spectra* “So, as you can see, when we energize different types of gasses, they emit different specific wavelengths of light.”
Me (INTJ): *whispering to ISTJ friend* “Well, that’s a gross oversimplification. Want to actually know how it all works?”
ISTJ Best Friend: “Not particularly, no.”
Me: “Aww, come on, but it’s really cool!”
ISTJ BF: *knowing I really like talking about this stuff* “Fine.”
Me: *psyched that she’s actually listening to me* “Ok, well when the gas is excited by the electricity going through the tube, the electrons jump to…” (end up explaining the theory why electrons can’t exist between energy levels)
ISTJ BF: “Woah there, I thought this was going to be a short, easy-to-follow explanation.”
Me:
ISTJ BF: “Yeah, I guess I should have figured. You just better hope he doesn’t put anything related to this as a short answer on the test. You’d never finish.”

5

Greetings everyone!

Spent time today working on the Philco 39-45. Decided to concentrate my efforts on the output section. This is where the radio signal goes through final amplification before running through the output transformer to the speaker. 

As you can see from the first few pictures, all of the components are old (original), and that blue capacitor you can see in the second picture is not supposed to be there. Some time in the past the owner added an ‘input’ for a record player which tied in through that capacitor to the speaker. The current owner didn’t want that accessory, so I removed it.

First I removed the output transformer so I could more easily get at the capacitors underneath. Then slowly went through and replaced the rest of the components. I ended up replacing pretty much everything since the capacitors were old, the resistors were out of tolerance (supposed to be 490k, measured over 700k), and the wires were shot.

In the last picture, I’ve got some parts soldered in, others are just twisted in place for now until I get all of the various layers of parts in place. It was a pretty time-consuming process since I had to remove everything, clean the terminals, then rebuild it. Don’t know if I’m going to do much on it this week since it’s supposed to be 100+deg most of the week, but I’ll post pics if I have them.

Till next time, stay tuned!

7

Progress!

Got a bunch of work done on the Philco 39-45 this weekend. Started out on Saturday replacing the decayed wires and an old resistor on the RF coil (first 2 pics). Then spent some time cleaning up the tuning capacitor.

I decided not to remove it, so I used a brush and paper towels and a bit of water to gently clean it up and remove the dust. It looks (and should function) quite a bit better now. Next I replaced some decayed rubber grommets for the mount that holds the tuning dial (last 2 pics). 

Today I mainly worked under the chassis. I got the last of the resistors and capacitors replaced, including the large power resistors. Next step will be to finish up wiring in the new power resistors and then put the power transformer back in. That means that hopefully soon, I’ll be able to do a power-up test and get to see if all of this work didn’t screw anything up. :D

Wish me luck and stay tuned!

youtube

This video was censored. I tried to make a video. Due to you tubes electronic censoring. Quic capture videos are now inpossible to make. Video was suppose to be 1:45 seconds long You tube makes them shorter rendering them ineffective. I"m going to get in touch with the people that arranged the 1st boycott to arrange a 2nd one. You tube needs to go back the way it was before.    

6

It’s ALIVE!!

Finally finished the bulk of the electrical restoration of the Philco 39-45. It’s taken almost 6 months of my spare time, but I replaced every capacitor, every resistor, and almost every wire. I fired the radio up for the first time last night and to my surprise/relief, it worked. 

I was able to tune in a station and it sounded clear, no hum or buzzing. First I powered it up slowly on my variac without the rectifier tube in place. This makes sure that the filament wiring is good (it was). Next I inserted the rectifier tube and again… slowly powered it up on the variac. Then I turned up the volume a bit and moved the tuning dial around. Was able to tune in a station immediately (even with no antenna attached). 

Needless to say I was pretty relieved. :)  

My next step is to solder the preset buttons back in, then tune each button to a specific station. I’m waiting on the owner to tell me which stations she would like me to tune in for each of the presets. 

Last steps will be the cabinet work. There’s some minor refinishing to do on the top of the cabinet, and I need to replace the worn-out grillcloth with the reproduction I got a few weeks ago. Then this radio will be ready to go back to its owner. 

Then… I’ll start on the GE-H32 that you guys all voted on in the poll.

Stay tuned!