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

Grunow 654
#16

Ok , That's a good idea.. I didn't really want to remove the IF cans anyway..

Thanks
Skip...
#17

(06-24-2015, 03:23 PM)vecher Wrote:  Ok Next problem .. Does anyone know how to remove the IF Cans??  See picture..

[Image: http://i292.photobucket.com/albums/mm38/...mlhiri.jpg]

Looks like you could compress the tabs but I was afraid of breaking them  .. Any thoughts??

Skip...

Skip;
  You won't break those tabs from compressing them, they are quite tough actually. A pair of duckbill pliers will do the job quite nicely. I would not sleeve the wires, the cans are easy enough to get open and it's also an opportunity to inspect the coil inside, and replace any resistors, and a grid lead.
Regards
Arran
#18

Ok, I removed the Cans.. Glad I did because the insulation was gone from one of wires..

[Image: http://i292.photobucket.com/albums/mm38/...mrtjji.jpg]

The wire going to the Grid cap was also frayed.. Did the 1st can already now will work on this one. Also found most of resistors have changed value.. The Mica caps were OK.. The dogbone resistors one that was 20K was reading 70K other was 5K reading 6.5 K..

So I will Keep moving Forward..

Skip...
#19

I tried to re-stuff the Caps on this.. However didn't go very well. So for now I just went with the right replacements under the chassis.. radio works very well. Performed alignment..

One question.. I did not replace the bias cell. How can you tell if its still working.. I pickup lots of stations on both bands and volume is load with no distortion..

Skip...
#20

Measure the voltage at the control grid at the 1st audio. If battery is good (haha) should see -1.5vdc. Watch batteries make good replacements.
Terry
#21

Terry, Ok thanks I will go out now and check..

Skip...
#22
Big Grin 

I measured -.5 volts using my Old Military VTVM TS-505.

According to schematic it should be -.2 Volts..

[Image: http://i292.photobucket.com/albums/mm38/...szm6qw.jpg]

These radio were run on 110 Volts AC I think so with my voltage higher it should be more?? The B+ should be around 250 Volts I measure about 330 volts.. I have a transformer I use on my 390's to step down the voltage .. I guess I will hook it up to radio to see what I get..

Anyway Radio work great..

Skip...
#23

(07-04-2015, 11:37 PM)vecher Wrote:  I measured -.5 volts using my Old Military VTVM TS-505.

According to schematic it should be -.2 Volts..

[Image: http://i292.photobucket.com/albums/mm38/...szm6qw.jpg]

These radio were run on 110 Volts AC  I think so with my voltage higher it should be more??  The B+ should be around 250 Volts  I measure about 330 volts.. I have a transformer I use on my 390's to step down the voltage .. I guess I will hook it up to radio to see what I get..

Anyway Radio work great..

Skip...

Skip;
  I think that the discrepancy may be explained by the different readings you get from using a DMM/VTVM verses an old fashioned Volt-Ohm meter which was what they typically used in the 1930s, the types they used loaded down whatever they were trying to measure. Radios from then were designed around a working line voltage of 117 Volts, except for 25 cycle versions which were designed around 115, the only power grids that were a true 110 volts were the DC power grids in some major cities.
Just out of curiousity, have you checked the tubes? One thing that can cause a higher then normal B+ voltage is a weak power output tube, a weak tube conducts less current.
Regards
Arran
#24

I did check the tubes. All were Good. However when checking them against schematic I noticed that I have a 6K6G in the place of a 6F6G. I believe it is a direct replacement but how it affects the voltage No clue..

I lowered the input voltage to 117 volts. The B+ now reads + 330 volts using a VTVM.. The bias reads -.68 volts.. Radio still works great.. So I guess its good for now.. I guess I will put it back in cabinet and back to living room..

Thanks all

Skip...
#25

(07-05-2015, 10:51 PM)vecher Wrote:  I did check the tubes. All were Good.  However when checking them against schematic I noticed that I have a 6K6G in the place of a 6F6G. I believe it is a direct replacement but how it affects the voltage   No clue..

I lowered the input voltage to 117 volts. The B+ now reads + 330 volts using a VTVM.. The bias reads -.68 volts..  Radio still works great.. So I guess its good for now..  I guess I will put it back in cabinet and back to living room..

Thanks all

Skip...

Skip;
  I think that we have found the answer as to why the B+ voltage is higher, lower current output tube. Find either a 6F6 or a 6V6 to replace the 6K6G, the 6K6G is not a direct replacement, the plate and screen current is lower then the 6F6 or the 6V6, and the heater current is also lower, the plate impedance is also wrong.
Regards
Arran
#26

Arran, Ok thanks . I will check to see what I have..

Skip...




Users browsing this thread:
[-]
Recent Posts
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
The list of my radio & TV collection!
Magical chords of forgotten melodies, old nostalgic music on an old radio... Saturday night blues on the Mid-Waves on an...RadioSvit — 12:20 PM
Philco 42-345 Restoration/Repair
Thank you MrFixr55 the issue with this radio is that the internal coil antenna is missing and there was a wire in its pl...osanders0311 — 11:34 AM
Philco 610B oscillator wiring
Regarding the oscillator circuit which is comprised of the 6A7's cathode, control grid, and screen grid. These elements ...Radioroslyn — 10:33 AM
Philco 42-345 Restoration/Repair
Hi OSanders, First off, welcome to the Philco Phorum where Phine Phamily-Phriendly Pholks Phull of Philco Phacts and P...MrFixr55 — 08:41 AM
Philco 42-345 Restoration/Repair
Today I've been reading through the site trying to learn more about this radio. I also soldered the lose power cord cabl...osanders0311 — 08:24 PM
Philco 610B oscillator wiring
Thanks David! I do have that same later prodution model 610 schematic. I've also studied the Philco service bulletins fo...Tubester — 08:12 PM
Philco 610B oscillator wiring
Some info from Beitmans says late production. David   David — 06:06 PM
Restoring Philco 96
Oh wow! Just found this thread.  Brings me back to early days on this phorum.  I did a 96 back in 2017.  Thread here: ...rfeenstra — 06:05 PM

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

>