Forums :: Resources :: Features :: Photo Gallery :: Vintage Radio Shows :: Archives
Support This Site: Contributors :: Advertise


It is currently May Fri 29, 2020 11:32 am


All times are UTC [ DST ]





Post New Topic Post Reply  [ 52 posts ]  Go to page 1, 2, 3  Next
Author Message
 Post subject: Philco 41-300
PostPosted: Mar Sun 08, 2020 3:40 am 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 188
Location: Portland, Oregon USA
Fast forward several years and I finally recapped and replaced the resistors in my 41 Philco. all that’s left is the block near the power supply and two paper caps hiding in the volume control area ( I’ll get to them eventually). I replaced probably 90% of the resistors as they were all drifting high. When I bought it I was able to get ( poor ) reception from overseas. I plugged it in And aside from the dirty volume control which got better with use, the AM sounds very good. However, I don’t get and stations on the other bands, although I get the background static suggesting I should. The schematics for this set suck frankly, and from what I can read, none of the tubes seem to be specific to any particular band. and the few caps/ resistors left should be affecting AM as well as other bands if they’re are truly bad. has anyone worked on this set or have suggestions of what to check first? Could be as simple as needing an antenna? It’s been out of the cabinet for so long I could have even just not connected the antenna correctly but I’m not seeing any loose/ disconnected wires.....thanks! Christopher


Top
 Profile  
 
 Post subject: Re: Philco 41-300
PostPosted: Mar Sun 08, 2020 3:46 am 
Member

Joined: Jul Mon 01, 2019 4:42 pm
Posts: 547
Location: St. Louis, MO
Did you align it after replacing all those components?


Top
 Profile  
 
 Post subject: Re: Philco 41-300
PostPosted: Mar Sun 08, 2020 3:55 am 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 188
Location: Portland, Oregon USA
No I didn’t. I knew how to do that in high school but it’s been over a decade since I’ve done that - so I’d have to research how to do it again. You mean the IF circuit/ cans , right? Would that make such a difference?


Top
 Profile  
 
 Post subject: Re: Philco 41-300
PostPosted: Mar Sun 08, 2020 4:04 am 
Member

Joined: Jul Mon 01, 2019 4:42 pm
Posts: 547
Location: St. Louis, MO
I'll put it this way. Aligning it could turn that static you heard into a clear station.

Yes, adding an antenna would help. In fact, most alignment procedures count on the alignment being done in the cabinet with the antenna attached.


Top
 Profile  
 
 Post subject: Re: Philco 41-300
PostPosted: Mar Sun 08, 2020 4:10 am 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 188
Location: Portland, Oregon USA
Is there anything in particular that triggers the need for an alignment? In the past I’ve only tended to replace caps ( and never really gotten any improvements from the few alignments I did) but this set had enough bad resistors that I decided to just replace most, I suppose that change in drift is enough to change reception.


Top
 Profile  
 
 Post subject: Re: Philco 41-300
PostPosted: Mar Sun 08, 2020 4:14 am 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 188
Location: Portland, Oregon USA
And since the AM is working does that at at least eliminate any of the IF cans?


Top
 Profile  
 
 Post subject: Re: Philco 41-300
PostPosted: Mar Sun 08, 2020 4:49 am 
Member

Joined: Jul Mon 01, 2019 4:42 pm
Posts: 547
Location: St. Louis, MO
Yes there is. Replacing the majority of the components would constitute the need for an alignment. The more you swap out/changes you make, the more an alignment is needed. Alignment isn't just for improving reception either. It can help make the dial accurate if that has also drifted.

If an alignment didn't help in the past, then your radio may have needed more work, or you may have just screwed up a step. Human error is always a possibility. I've done it myself. As for needing more work, you may have to peek under those IF cans. Sometimes resistors and caps can hide underneath. I had a resistor inside one can of a Philco 40-160 I worked on a few months ago.


Top
 Profile  
 
 Post subject: Re: Philco 41-300
PostPosted: Mar Sun 08, 2020 7:25 am 
Member
User avatar

Joined: Jan Thu 01, 1970 1:00 am
Posts: 34880
Location: SoCal, 91387
This set apparently has four bands, BCB and three S/W. I would suggest switching it to the 9-12 MC band, tune to 10 megacycles, and see if you can get WWV. If not, connect as long an antenna wire as you can, and try for it. All bands are using both the loop, and have a connection for an external wire antenna.

AFA aligning, consider that component values drift over time, so alignment, both RF and IF, is indicated in order to do a professional job in restoration.

Here's a link to the service instructions, which include directions for alignment;
http://www.nostalgiaair.org/pagesbymode ... 013423.pdf

_________________
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\He Who Dies With The Most Radios Wins/////////////////////////


Top
 Profile  
 
 Post subject: Re: Philco 41-300
PostPosted: Mar Sun 08, 2020 6:20 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 188
Location: Portland, Oregon USA
I had to look up what WWV is but I think I may have heard that last night, not really knowing any better. Wiki has a sample, and while I didn’t hear any voice playing over the air I heard an odd/ creepy ticking which was present in the sample audio. I’ll pay more attention today


Top
 Profile  
 
 Post subject: Re: Philco 41-300
PostPosted: Mar Sun 08, 2020 6:26 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 188
Location: Portland, Oregon USA
I should also follow up with why would I be hearing that station but not others? What’s the significance?


Top
 Profile  
 
 Post subject: Re: Philco 41-300
PostPosted: Mar Sun 08, 2020 6:50 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 188
Location: Portland, Oregon USA
So the wwv comes in weakly and blurry at 10kc. I also get something weak and blurry at around 16.5 kc in a foreign language. Does this sound like classic mid alignment !?!


Top
 Profile  
 
 Post subject: Re: Philco 41-300
PostPosted: Mar Sun 08, 2020 7:07 pm 
Member
User avatar

Joined: Jan Tue 31, 2012 1:55 am
Posts: 12672
Location: Mountains of Mourne. Ireland.
A legible (printer friendly) service manual for model 41-300 can be downloaded from Tom Bavis' website, in DjVu format.
https://tinyurl.com/tom-bavis

I use this DjVu reader (safe download from sourceforge.net) works great.
http://antiqueradios.com/forums/viewtop ... 9#p2746819


:) Greg.
If you are using a Windows computer, here is a direct link to the DjVu reader .exe file.
https://sourceforge.net/projects/djvu/f ... rror=netix

Save it to your desktop, open it and follow the installation instructions.


Top
 Profile  
 
 Post subject: Re: Philco 41-300
PostPosted: Mar Sun 08, 2020 7:42 pm 
Member

Joined: May Fri 01, 2015 2:33 am
Posts: 1559
Location: Roslyn,Pa 19001
I did a 41-300 a few yrs ago and it's one of my favorites. Great player and has a built in ant so you wouldn't necessarily need an external ant connected to it. As others have mentioned I would go thru and do the if and rf alignment and test the tubes. On my set the XXL's and 7B7's where pretty weak and made a big improvement when replaced. I'm not saying that this is an issue w/your set but it's a possibility. You will need to get a signal generator (if you don't have one) to do the IF alignment. https://philcoradio.com/phorum/showthre ... ght=41-300

Bear in mind any of the service literature was printed for the folks that made a living fixing these sets in the day when it was cutting edge technology. These guys could at a glance tell what did what and why a particular part was used rather than another in short they knew radios inside and out. It wasn't printed for hobbyist 70yrs later.
https://philcoradio.com/library/downloa ... 20Book.pdf
On all of the '300 schematics they are missing the connection from the vc to the output transformer. Pretend it's there.

Terry


Last edited by Radioroslyn on Mar Sun 08, 2020 7:47 pm, edited 1 time in total.

Top
 Profile  
 
 Post subject: Re: Philco 41-300
PostPosted: Mar Sun 08, 2020 7:44 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 188
Location: Portland, Oregon USA
I have a HealthKit SG 8 that I’ve never used so learning how to use it and will attempt my first legit alignment soon.


Top
 Profile  
 
 Post subject: Re: Philco 41-300
PostPosted: Mar Sun 08, 2020 8:33 pm 
Member
User avatar

Joined: Jan Tue 31, 2012 1:55 am
Posts: 12672
Location: Mountains of Mourne. Ireland.
Two excellent alignment procedure videos (not found with a Google or YouTube search).
http://antiqueradios.com/forums/viewtop ... 1#p2645421

Greg.


Top
 Profile  
 
 Post subject: Re: Philco 41-300
PostPosted: Mar Sun 08, 2020 10:03 pm 
Member
User avatar

Joined: Jan Thu 01, 1970 1:00 am
Posts: 34880
Location: SoCal, 91387
delco1946 wrote:
I should also follow up with why would I be hearing that station but not others? What’s the significance?

The WWV time signal consists of a ticking sound for the seconds, and then an announcement of the current time, continuously.

You had posted earlier that you were unable to get anything on the shortwave bands, so that's why I suggested that you try to dial in WWV, which is always there, and since it is in Fort Collins, Colorado, isn't too far away from your location. You might also try it on 5 Megacycles as well. It simply proves that your SW bands are indeed functioning.

There's no longer a helluva lot of broadcasts on SW, but you should be at least picking up a few signals. What exactly are you using for an external antenna, if you are, and in what time period are you listening?

AFA the tubes, I would suggest replacing the two XXL/7A4's, and the two 7B7's. I've generally found that replacing the converter and IF tubes usually marks an improvement in sensitivity.

_________________
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\He Who Dies With The Most Radios Wins/////////////////////////


Top
 Profile  
 
 Post subject: Re: Philco 41-300
PostPosted: Mar Mon 09, 2020 1:07 am 
Member

Joined: Jul Mon 01, 2019 4:42 pm
Posts: 547
Location: St. Louis, MO
delco1946 wrote:
I have a HealthKit SG 8 that I’ve never used so learning how to use it and will attempt my first legit alignment soon.


FYI, this may need to be recapped and aligned as well if it's never been done. Do you have a frequency counter? If not, you can get a cymometer off of eBay for cheap. Power it with a wallwart.

It's important that the signal generator is accurate as you will be assuming that the frequency that you're setting its dial to and using to align your radio is accurate.


Top
 Profile  
 
 Post subject: Re: Philco 41-300
PostPosted: Mar Mon 09, 2020 3:35 am 
Member
User avatar

Joined: Jan Thu 01, 1970 1:00 am
Posts: 34880
Location: SoCal, 91387
The generator's frequency output can be measured by simply using a digital readout AM radio. Set it to 910 kilocycles, and the generator to 455, then see if the radio picks up the tone on that second harmonic, with the generators hot probe next to the radio.

_________________
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\He Who Dies With The Most Radios Wins/////////////////////////


Top
 Profile  
 
 Post subject: Re: Philco 41-300
PostPosted: Mar Mon 09, 2020 3:51 am 
Member

Joined: Jun Mon 01, 2015 9:34 pm
Posts: 1262
Location: Greenville, TX
Do not think anyone mentioned it but the loop antenna in the cabinet needs to be connected in addition to the external antenna.

_________________
Dale

http://www.dalesantiqueradio.com/


Top
 Profile  
 
 Post subject: Re: Philco 41-300
PostPosted: Mar Mon 09, 2020 6:14 am 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 188
Location: Portland, Oregon USA
Well my signal generator should be working correctly, I actually paid a guy to recap it and check out on the Oregon coast. However at the moment I can’t find the leads that go with it :shock: I’ll keep looking - hope I have it! I don’t have an external antenna and it’s currently in the basement if that might affect shortwave. The AM is working great. I’ve tuned the shortwave in in the morning and evening West coast time. Only 2 stations come in and are weak and blurry - I’m connected to the internal antenna.. I’ll have to see if I have spare tubes but may have to buy some. If the tubes were bad then I would assume AM would also be affected right? I’m not really seeing tubes/ parts that are totally specific to the shortwave, but I could be missing something.


Top
 Profile  
 
Post New Topic Post Reply  [ 52 posts ]  Moderators: Marcc, Norm Leal Go to page 1, 2, 3  Next

All times are UTC [ DST ]


Who is online

Users browsing this forum: Chris108 and 16 guests



Search for:
Jump to:  


































-->


Privacy Policy :: Powered by phpBB