Model 16X - Problem With Radio Reception - Printable Version
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Model 16X - Problem With Radio Reception - Sonnyboy - 02-02-2011
I recently purchased a Philco model 16x console radio. It powered up fine, and the radio worked on AM, but the reception was very spotty, lot's of static, and the SW stations had no reception. So I obtained the schematics and I have now replaced all of the old electrolytic, paper, and bakelight capacitors. However, when I finished the replacements and powered up, I have no radio reception at all. The lights work, power seems fine with nothing smoking or anything, and the speaker is working as I can get some humm in it when connected.
I now wish that I had checked the reception after every single cap replacement to help isolate the problem. However, too late for that. I have checked and re-checked all of the cap values and my connections and can't seem to find the problem. Since I had to rebuild the support grommets and the rubber dial drives on the tuning condenser I thought I may have loosened a wire there somewhere, but again all seems to be ok.
Your thoughts please...can you point me to where I should be looking, the most likely location of the problem? Thanks very much, Sonny
Re: Problem With Radio Reception - Ron Ramirez - 02-02-2011
Without actually having the chassis in front of one of us, no one here can tell you exactly where the problem is.
All I can tell you is to very carefully trace out all of the connections, following the schematic. Something must have been miswired if it worked before it was recapped but doesn't work now. Check solder connections for good joints, and make sure there are no solder blobs shorting something out.
If this doesn't help, then it's time to start tracing using a signal tracer and signal generator. If you do not have either, you may need to find someone in your area to help you by looking over your shoulder and actually helping to look over the chassis.
Re: Problem With Radio Reception - Sonnyboy - 02-02-2011
Thanks for your thoughts Ron. I will continue to carefully check the connections. I am a rookie at this with no formal electronic training (bet you already guessed that), but I am very good at figuring out things in a logical fashion and am enjoying this project. This is the second radio I have reconstructed...the first is working great!
Part of my problem with this reconstruction is that my radio is a Philco 16X with a 222 chassis, and I have not actually been able to find a schematic that is exactly the same. The schematic that I have been using is for a 121 and 122 Chassis, but other than a couple of new parts changes in later service bulletins it appears to be very close in the parts lists and the schematic. If anybody reading this has an actual schematic for the 222 that could obviously be very helpful.
Also, another rookie question. This chassis has 2 electrolytic cans. On the bottom of each can there is a center post (1 actually has a screw in it), and then another post on the outer edge of the can that appears to be attached to the can itself. My guess was that the outer posts are the grounds and the center the live feed...but I'm not sure. Anybody care to give me some thoughts on this?
Thanks for your help. I will appreciate any help and advice (other than "quit", LOL) from you experts! Sonny
Re: Problem With Radio Reception - Ron Ramirez - 02-02-2011
Code 222? I've never heard of such a thing. Is this 16 an export model, or other than a USA set?
As for the electrolytics, the center terminal is positive; the can (terminals at the outer edge of the can) is negative. The negative terminals of the two main electrolytics connect to B-, not to chassis ground.
Re: Problem With Radio Reception - Sonnyboy - 02-05-2011
Ron. Thanks for your thoughts on the electrolytic cans...very helpful. However, I have another complication with them that causes me confusion on the connections.
The 2 electrolytic cans were originally parts #87 and #88, #30-2014 condensers with values of 8mfd 500v on this chassis. In a later change noted on a service bulletin, part #87 was changed to #30-2067 with values of 10mfd 15v. The bulletin said that the connections remain the same as before. That is my problem. When I look at the bottom of 30-2014 there is 1 post on the side of the can and 1 center contact with a screw and nut on it...pretty straightforward when I put in the new cap with 2 wire leads going to 2 contacts. However, on the bottom of #30-2067 there are 3 contacts. 1 contact is the post on the side, but there are 2 contacts in the center...1 is silver in the very center, and the other is blue sitting a little off center towards the edge of the can. When I install the new cap I am unsure as to where to attach the two leads and which end is ground, or is there no ground at all?
Also I replaced 2 old paper caps part #30-4020 in another area of the chassis. They are green and about 1 1/2 inch long with a black stripe on 1 end. When I replaced them I assumed that the black stripe end was the lead to ground, similar to the markings on the newer ones I am using as replacements. Now that I am having the "no reception" problem I am wondering if that was a good assumption.
I appreciate any help you can offer on these 2 questions. As always, thanks for your thoughts and thanks to anyone else who can offer some help. Sonny
Re: Problem With Radio Reception - Ron Ramirez - 02-05-2011
Sonny, you haven't answered this question yet:
Quote:Code 222? I've never heard of such a thing. Is this 16 an export model, or other than a USA set?
After spending an hour looking through my copy of the Philco Changes in Models package (available here as a free download to registered Phorum members), various Philco parts catalogs, etc., and not finding a 30-2067, I finally found the note in Rider's volume IV, Philco page 4-8.
That change applied only to Model 16A, a 25 cycle AC version of Model 16. Also, the replacement 30-2067 could not possibly have been rated at only 15 volts. It would have blown sky high as soon as power was applied and it was hit with rippling DC on the order of 400 or more volts!
Now, condensers (75) and ( 88 ) were replaced by a single condenser, part no. 30-2045 in the Baby Grand model, and 30-2046 in the console and chairside models. This is a two-section condenser with two positive terminals. Condenser 30-2045 contained an 8 uF, 450 volt cap and a 10 uF, 50 volt cap. Part 30-2046 is the same except the 8 uF section is rated at 475 volts.
The positive terminal of the 10 uF, 50 volt section of this cap connects to chassis ground. This is important! The positive terminal of the 8 uF section (which you can replace with a 10 uF, 450 or 500 volt electrolytic, depending on what you are working on) connects as condenser ( 88 ) did originally.
Now let's examine the two 30-4020 caps. Did one end of each of these two caps originally connect to ground? When you replace a component, you must connect it to the same points in the circuit as the original, and never assume anything.
Re: Problem With Radio Reception - Sonnyboy - 02-06-2011
Hi Ron. Thanks so much for spending all of this time on my questions. I really appreciate your interest and your help.
About code 222...these numbers are stamped in ink on the outside of my chassis, along with the letters OK. Perhaps this is just some sort of an inspection notation or something. I have studied the chassis and the schematics extensively I am sure it is a code 121.
The 2 electrolyctic cans that I mentioned are parts #'s 87 and 88. #88 is 30-2014, and #87 is updated with 30-2046 (this is the part number I finally found on the can). I had said earlier it must be 30-2067 after reading the service bulletin update, however, the part # I was able to read on the can is 30-2046 as you noted after your research. I was using 1 10uf 500 volt cap to replace this one, so I will have to get an additional 10uf 50 volt cap and connect as you noted.
The 2 30-4020 paper caps are green and have a black stripe on one end. In 1 location the striped end was attached to ground. In the other location the striped end was attached to the lead of the volume control and the other end to a resister. In both of these I attached the new caps with the black striped end positioned exactly as the old green paper caps were attached.
Ron, again thanks so much for the time you are spending with me on this. I will try to connect the electrolytic can 30-2046 correctly and see if that clears up my problem. I have checked and re-checked every other connection over and over again, so I hope this helps. Please let me know if you have any other thoughts about why the reception signal is not getting through. Thanks, Sonny
Re: Model 16X - Problem With Radio Reception - Ron Ramirez - 02-06-2011
I just noticed you said in your original post that it is a 16X.
So it would be a Code 122 if it is a 5-band chassis.After you check the electrolytic connections, if you still have no reception it may be time to call in a mentor. Where are you located?
Re: Model 16X - Problem With Radio Reception - Sonnyboy - 02-07-2011
Hi Ron. I am located in Atlanta, Georgia.. It would be great to find someone who could in fact be a mentor. I have not had any luck with this so far.
Thanks again for your help. I really appreciate these old radios and enjoy tinkering with them, so I am really trying to not get too discouraged and give up.
Sonny
Re: Model 16X - Problem With Radio Reception - Ron Ramirez - 02-07-2011
Are you a member of SARS (Southeastern Antique Radio Society)?
http://www.sarsradio.com/
I've been to a couple of their meets; they seem to be a great group of people. Surely one of them would be willing to help you one-on-one with this.
They are having a swap meet on February 26th. I would go if it weren't such a long drive for me.
Re: Model 16X - Problem With Radio Reception - Sonnyboy - 02-08-2011
Thanks Ron. I'll try to contact them.
Re: Model 16X - Problem With Radio Reception - Sonnyboy - 02-09-2011
Hi Ron. Good news...I found/fixed the problem I had with my Philco 16X Radio
! I found that I had grounded to chassis both negative leads of one of the double cap bakelights I had installed when only one of them should have gone to ground. As soon as I changed this connection the radio reception came back, and came back very well. I have full reception on all 5 bands with lots of stations on each....and it sounds great!By the way, before I found this bakelight problem I also made the addition to the electrolytic cap #57 and #88 that you had guided me to. And while it probably helped overall, it still did not fix the "no reception" problem that I had caused and I still had no signal. Thus I went back to pouring over
every connection again and I found the bakelight problem.I guess the moral of this story is where possible never change more than one cap at a time, and keep checking the radion reception after each change. I also have made contact with the SARS group here in Atlanta and will be getting involved with them.
But again, thanks so much for this website, and for the work that you do. You are a terrific resource and I really appreciate your help. I will probably be asking you a dumb question again sometime in the future...but as I do more of these restorations perhaps I can answer a question somebody else has as well. Sonny
Re: Model 16X - Problem With Radio Reception - Ron Ramirez - 02-09-2011
Good, Sonny. I'm glad you found and fixed the problem.
Yes, you should join SARS and get acquainted with the fine folks there. We should all be so lucky, to have a radio club in our backyards. I rejoined the Indiana Historical Radio Society last year, and they are having a meet this Saturday. Trouble is, Indy is a 3+ hour drive for me...
And with gas locally at $3.15/gallon and rising, I'm leaning against making the trip.
Re: Model 16X - Problem With Radio Reception - Sonnyboy - 02-09-2011
HI again Ron. Well the good news is that I have reception on all 5 bads. However, now that I have had more time to play with it I notice that I am not getting any stations when I go to the left or below 70 on the AM scale. I get stations very clearly all around the dial to the right or up on AM, but when I go left or down from 70 I get loud static and no stations when I can easily get them on other radios using the same location and antenna
.So, I'm really happy with what I am getting, but I want to make this thing 100% right. Sorry to trouble you again but any quick thoughts about where I should look? Is there a particular circuit or tube or detector or anything that would be associated with this portion of the AM band?
By the way, I am going to the SARS meeting next week. I told them that I had been using your websight and of your help... Thanks again, Sonny
Re: Model 16X - Problem With Radio Reception - Ron Ramirez - 02-09-2011
That is a tell-tale sign of tuning condenser plates rubbing against each other and shorting out.
It can (usually) be fixed if the damage is minor, and 99% of the time it is. The bent plates can (again, usually) be straightened out so that they no longer rub together. However, this is not a job for a novice. You should get one of those SARS fellows to look at the chassis and help you out here. This is not something I can talk you through, unfortunately.