Posts: 451
Threads: 85
Joined: Nov 2011
City: Cumming, GA
I have a Philco 42-327 Rider 14-31 http://www.nostalgiaair.org/PagesByModel...013515.pdf
Changed the caps and replaced a couple of missing tubes and powered up the radio and got static no smoke so far so good. It works on the sw as I have gotten some foreign broadcast at the high end of the scale. On BC I get static, set the signal gen to 455 and got tone at 480 with the gang fully closed should I be able to adjust this down using 24 A&B because it doesn't seem to move the signal just fade it in and out?
Eric
Posts: 7,303
Threads: 269
Joined: Dec 2009
City: Roslyn Pa
Did you try moving the generator down a bit then repeaking the trimmers on both IF's?
Terry
Posts: 451
Threads: 85
Joined: Nov 2011
City: Cumming, GA
Yes I did, the tone will fade as I turn the screw (24B) but when I turn the dial on the signal gen it doesn't follow. 24A doesn't seem do anything?
Posts: 7,303
Threads: 269
Joined: Dec 2009
City: Roslyn Pa
Do you have plate voltage on both plates of the mixer tube?? Where are you injecting the IF signal??
Terry
Posts: 4,909
Threads: 54
Joined: Sep 2008
City: Sandwick, BC, CA
These sets are a bit weird, they don't use a conventional convertor tube they use a dual triode mixer oscillator tube called an XXD/14AF7, they also have an extra IF amplifier stage. A stupid question but is the band switch set on dial tuning instead of pushbutton tuning? There are three IF transformers, the first has two trimmers but the second and third ones have one trimmer each marked 29A and 35A respectively, the 455 kc signal should go into the antenna section of the tuning capacitor.
Regards
Arran
(This post was last modified: 02-07-2013, 11:59 PM by Arran.)
Posts: 4,909
Threads: 54
Joined: Sep 2008
City: Sandwick, BC, CA
It is entirely possible that the oscillator for the broadcast band isn't functioning for some reason, a bad resistor, a bad mica cap, or even an open oscillator coil could cause this. I would start checking voltages on the XXD tube, particularly the oscillator section.
Regards
Arran
Posts: 272
Threads: 12
Joined: Nov 2005
City: Nashville, TN
Hi Eric,
Check the tube pins and make sure they are clean. Loktals are know to sometimes have a little corrosion in them, causing bad contact. Something simple to check.
Posts: 893
Threads: 9
Joined: Mar 2008
City: Vieques, PR USA
State, Province, Country: PR
Agree you need to realign the IF and check all the things mentioned. I once had a 42-327 that had the same symptoms as yours and mine turned out to be the local oscillator was not working on BCB but was fine on SW. Bad mica cap.
Posts: 451
Threads: 85
Joined: Nov 2011
City: Cumming, GA
Got a lot of things to check now. Thanks to all I will post when I know more
Posts: 451
Threads: 85
Joined: Nov 2011
City: Cumming, GA
Ok, when I started to see what the voltages were on the XXD and put the meter lead on pin 4 the radio started playing and you could tune in stations I followed it back to the OSC lead #6 is this an indication of an open winding?
Posts: 451
Threads: 85
Joined: Nov 2011
City: Cumming, GA
This morning started looking at the OSC and the mica caps especially at point 6 on the OSC first checked #9 and it came in at 260pf. Then # 5on the print calls for 5pf but the dots on the cap say it should be 100 pf but reads 19pf so I put in a 10 and nothing then put in a 100 and the radio plays fine. Thanks for the help now to clean the chassis and the cabinet. Love this site!
Eric
Posts: 2,128
Threads: 18
Joined: Oct 2008
City: Merrick, Long Island, NY
Me too, was on my Philco. SSDD. Glad you gort it working.
Posts: 893
Threads: 9
Joined: Mar 2008
City: Vieques, PR USA
State, Province, Country: PR
Congrats, Eric. I can't recall which was my bad cap...I'm thinking it was #9. What I remember most is that it was the most buried one in that part of the circuit!
Users browsing this thread: 1 Guest(s)
|
|
Recent Posts
|
|
1949 Motorola 5A9M
|
| Hello All;
I found the CMB41L down in the basement, it is definitely a 1950-51 model, the capacitors have date codes ...Arran — 07:48 PM |
|
Philco 42-345 Restoration/Repair
|
| Hi, all the caps I order, other than the electrolytics, are of the 630V rating. No worries on it being too high, and no ...gary rabbitt — 05:46 PM |
|
Philco 42-345 Restoration/Repair
|
| Hi, there's a lot to consider when designing these circuits so you shouldn't have a lot of concern when replacing caps. ...RodB — 02:03 PM |
|
Philco 42-345 Restoration/Repair
|
| I have ordered and received new caps for this radio and hope I've ordered the correct ones. I tried matching them to the...osanders0311 — 11:35 AM |
|
Philco newbie with P-1891-WA console questions
|
| Hello Jeff ,
Far as the Electrolytic capacitors go here is a list of parts.
that will work . I like using Nichicon and...radiorich — 09:50 PM |
|
Philco newbie with P-1891-WA console questions
|
| Well, I've been stumped at trying to get the first of 11 electrolytic capacitors. I got a schematic and have a list of t...Jeffcon — 07:54 PM |
|
Model 80 Antenna Issue?
|
| Thanks Gary and Rod.
I also found an article in the Philco Repair Bench under Service Hints and Tips, about installi...Hamilton — 12:32 PM |
|
Model 80 Antenna Issue?
|
| Hello Hamilton, here is a little information found in our Philco Radio Library at the bottom of the Home page. Hope it ...GarySP — 11:28 AM |
|
Model 80 Antenna Issue?
|
| I did as you suggested and touching the middle of the volume control did nothing so the coil has to be rewound. Any idea...Hamilton — 10:19 AM |
|
1949 Motorola 5A9M
|
| This would be the second portable in the "other radios" forum where I have a similar one in my collection. I h...Arran — 12:41 AM |
|
Who's Online
|
| There are currently no members online. |
|
 
|
![[-]](https://philcoradio.com/phorum/images/bootbb/collapse.png "[-]")
