Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

Thread Closed
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Philco model 610 rebuild - by Tim P.
#61

OK, you gotta go and scratch that itch! Let's fire it up!
I can barely wait to fire up mine.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
#62

Alright - it's time! Drum roll!!! Lets see what has been accomplished with all this work, time and effort. What's in the box??? Well, here goes, probably for the first time in 50 years, this ol' 610 will see power. Meters in place, plugged into the variac ... 25v ...30...35...40...ok, reposition a meter. 45v ...B+ coming up, 25v. Have meters on the output tube plate, input cap and output cap. Sniffing - so far so good. Up to 50ac,  40 on B+ ... 55v, B+ up to 70, then dropping back to 60 .. huh. Now, 60v line, went up to 90v B+, dropped back to 85. Ok, up to 65 ac, B+ 122, I can hear a very faint squeal when I rotate the volume control - there seems to be life at this point! AC 70, B+ 155, squeal changing. 75v...80...oops! I forgot to put on the tube shields. Well, now I loosened a  top cap on a tube UGH!

Ok, tube shields in place, still squealing. This doesn't sound good .... Ok, I flip the tone control in, and the squeal disappears. Interesting. I get some static if I touch the antenna terminal. ...now at 90v rotating tuner with antenna wire connected ... I FOUND A STATION!!! Alright, now 95v ... a little louder and clear. 105v ac, 285 B+. 110ac, 298 B+. Well, it looks like I am on shortwave and picking up some stations - in Spanish! Icon_smile

Now, a "bad" observation. - I have a horrible squeal when I turn the tone control taking the cap out, if I leave it in, it goes away. Obviously some bugs to work out, but there is definatly life in this old thing!  Well, this is where I am going to leave things for tonight.

If I could find the place called "Somewhere", I could find "Anything" Icon_confused

Tim

Jesus cried out and said, "Whoever believes in me , believes not in me but in him who sent me" John 12:44
#63

Tim, the first thing to come to mind, make sure the grid wire to the 75 tube is routed inside the tube shield.

Steve

M R Radios   C M Tubes
#64

It's outside. Could be the problem. It is a feedback of some kind. Ill try to running it inside an see if it helps.

If I could find the place called "Somewhere", I could find "Anything" Icon_confused

Tim

Jesus cried out and said, "Whoever believes in me , believes not in me but in him who sent me" John 12:44
#65

Usually the 75 is next to the output tetrode (or pentode) and so the grid wire picks up the output signal which creates positive feedback and oscillation. Leaving the grid wire inside the shield reduces that feedback.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
#66

Steve, Mike, you guys were dead on! I rerouted the grid wire of the 75 inside the shield and the oscillation went away. I don't know if I would have figured that one out on my own or not. Thank you!

I need to get brave and flip the band switch (probably ought to DeOx it) and see what I have on broadcast. I am sure it will need alignment (or at least touched up), and burned in. So far, it sounds good, esp considering the history of this poor thing.

One other question - what to use to clean this dirty thing?
   
I had read somewhere maybe mineral spirits. I found out real quick that window cleaner cleans really good, including the dial markings. Yea, I fogged it, but thankfully I only rubbed the bottom with the part numbers, which cleaned off nicely. Any suggestions? The worst is a dark spot, which I don't know if it is dirt, sun damage or just age.

If I could find the place called "Somewhere", I could find "Anything" Icon_confused

Tim

Jesus cried out and said, "Whoever believes in me , believes not in me but in him who sent me" John 12:44
#67

It is likely sun plus dial lght, as it likely was kept there due to being the favorite spot. I don't think it can be cleaned. As for dirt, yes, mineral spirits.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
#68

I learned that one the hard way. It was a 19, it had me stumped for a week before I stumbled onto the cause.

Steve

M R Radios   C M Tubes
#69

I finally had a chance to get back on this project. Started feeling nostalgic and had a few minutes to burn, even had the wife's blessing  Icon_razz 
I decided the original dial needed replaced and found a very nice repro from Radio Daze. I had to slightly enlarge the locating holes with a 5/32 drill bit. It was slightly thicker, but went on fine.
     
   
One thing I noted: The two guides at the top of the dial were each bent down, and I discovered that this scratched off some of the lettering before I realized what was happening. They are suppose to be straight out, where they guide the dial on the unprinted edge. Learn from my mistake. 
   

I found the band switch to be dirty so I hit it with deoxit, seemed to help. It works pretty good on the BC band, but not so much on either SW band. I do get some stations, but not very sensitive. It may be my antenna. In the center band I get some bleed through from the BC band, but I dont know if there are really any stations there anyway. The AM is pretty sensitive and picks up a lot of stations. It may need the alignment touched up, but it does work now after how many decades of silence?  Icon_thumbup More to come ...

If I could find the place called "Somewhere", I could find "Anything" Icon_confused

Tim

Jesus cried out and said, "Whoever believes in me , believes not in me but in him who sent me" John 12:44
#70

Hmmm...maybe we should start gluing some felt to the inside of those metal guides to protect those expensive dial scales?

--
Ron Ramirez
Ferdinand IN
#71

One thing is for sure, those dials are NOT cheap, so some felt may not be a bad idea. Thanks for the suggestion Ron! I think it is easy to bend those tabs while working on a chassis without even knowing it. I am sure this happened in a previous repair. It's something to watch for at least.

I did an alignment attempt last night. I didn't see a real day or night difference other than I think I had the dial off position a little bit. I may need to move it and touch up. May not make a difference either. I set the dial by tuning in a station that I knew the location. Anyway, I may leave it alone unless there are reasons to reset.

If I could find the place called "Somewhere", I could find "Anything" Icon_confused

Tim

Jesus cried out and said, "Whoever believes in me , believes not in me but in him who sent me" John 12:44




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Need to purchase some accessories for restoration of my Old Philco Radio
Here is a list of resources found in our online library that you might find useful. Mike's Gobs of Knobs email addres...klondike98 — 01:46 PM
First Radio restoration
Hi Tubeman, Welcome to the Philco Phorum.  Phamily Phriendly Pfun with Phine Pholks Phull of Philco Phacts. (See a p...MrFixr55 — 12:33 PM
First Radio restoration
You could post in the WANTED ADs section here on the Phorum and see if anyone has an RF generator that they want to sell...klondike98 — 11:55 AM
Zenith H725
Good ideas, thank you Arrange and Rich. I have the adhesive aluminum foil already and can try that immediately. More ...EdHolland — 10:18 AM
Graphics for majestic 1050 dial glass.
Murf; I found this thread on the ARF, the first photo has a pretty good view of the dial glass. Regards ArranArran — 01:12 AM
Zenith H725
hello Ed, how about that speacial tape used for ducting it's like foil or how about thin piece of aluminum roof flash...radiorich — 12:19 AM
Zenith H725
Ed; One material that I have seen, but never tried for this was material for making exhaust gaskets, it's similar to ...Arran — 11:42 PM
Zenith H725
I just remembered, I have some hi temp silicone rubber material which could do the trick. Or a piece of FR4 laminate. Th...EdHolland — 08:39 PM
Zenith H725
The PSU filter cap arrived today (thank you USPS!) so I will work on that later. Meanwhile, I have the dial, speaker...EdHolland — 06:42 PM
Philco 610B oscillator wiring
Thanks Terry. After checking my notes I think I recorded about -10v at the 6A7 G4/control grid. The screen grid (G3 &...Tubester — 05:59 PM

[-]
Who's Online
There are currently no members online.

>