Allwave 23 RF diode adjustment - EH Scott Radio Enthusiasts2024-03-29T12:39:45Zhttps://ehscott.ning.com/forum/topics/allwave-23-rf-diode-adjustment?commentId=3925821%3AComment%3A45746&feed=yes&xn_auth=noUpdate to old post, I did hav…tag:ehscott.ning.com,2022-09-20:3925821:Comment:1285502022-09-20T14:17:36.982ZLou deGonzaguehttps://ehscott.ning.com/profile/LoudeGonzague
<p>Update to old post, I did have a NOS control and installed it in the set at the owners house. That was 7 years ago so I guess my work has held up(along with 23 tubes)!</p>
<p>Update to old post, I did have a NOS control and installed it in the set at the owners house. That was 7 years ago so I guess my work has held up(along with 23 tubes)!</p> I installed the radio back in…tag:ehscott.ning.com,2015-01-24:3925821:Comment:467142015-01-24T17:38:30.753ZLou deGonzaguehttps://ehscott.ning.com/profile/LoudeGonzague
<p>I installed the radio back in the cabinet a couple weeks ago and thought everything was fine. I got a call this morning that the volume control is apparently bad. It was a replacement probably done in the late 50's so I thought it was ok with just a shot of cleaner. But as soon as you come off zero the volume jumps up and with as much power as this radio has it's pretty bad. I noticed this radio uses a fairly low value, 100K. I wonder if others have had this trouble and if there were…</p>
<p>I installed the radio back in the cabinet a couple weeks ago and thought everything was fine. I got a call this morning that the volume control is apparently bad. It was a replacement probably done in the late 50's so I thought it was ok with just a shot of cleaner. But as soon as you come off zero the volume jumps up and with as much power as this radio has it's pretty bad. I noticed this radio uses a fairly low value, 100K. I wonder if others have had this trouble and if there were any mods to reduce the gain a little since there is so much power available in this set. Anyway the radio is on the third floor of an old house so I will try and replace the control at the site. I'll check my parts for an audio taper 100K pot, it's too bad I don't have my stuff better organized as it may take a few hours to look for it, ha ha!</p> The dial escutcheon held a pi…tag:ehscott.ning.com,2015-01-10:3925821:Comment:463722015-01-10T21:27:37.209ZNorman S Braithwaitehttps://ehscott.ning.com/profile/NormanSBraithwaite
<p>The dial escutcheon held a piece of isinglass on which both the dial scale and meter needle were projected. Without a front panel and escutcheon, a piece of frosted mylar or other similar translucent material is required for viewing the dial and meter.</p>
<p>Norman</p>
<p>The dial escutcheon held a piece of isinglass on which both the dial scale and meter needle were projected. Without a front panel and escutcheon, a piece of frosted mylar or other similar translucent material is required for viewing the dial and meter.</p>
<p>Norman</p> That's good to know, I though…tag:ehscott.ning.com,2015-01-10:3925821:Comment:461602015-01-10T21:08:15.628ZLou deGonzaguehttps://ehscott.ning.com/profile/LoudeGonzague
<p>That's good to know, I thought a coil would be very hard to find! Here is a pic of the dial. Was there any type of screen over the strength meter or bulb? There is a 44 lamp in there now<a target="_self" href="http://storage.ning.com/topology/rest/1.0/file/get/2771122820?profile=original"><img width="721" class="align-full" src="http://storage.ning.com/topology/rest/1.0/file/get/2771122820?profile=RESIZE_1024x1024" width="721"/></a></p>
<p>That's good to know, I thought a coil would be very hard to find! Here is a pic of the dial. Was there any type of screen over the strength meter or bulb? There is a 44 lamp in there now<a target="_self" href="http://storage.ning.com/topology/rest/1.0/file/get/2771122820?profile=original"><img width="721" class="align-full" src="http://storage.ning.com/topology/rest/1.0/file/get/2771122820?profile=RESIZE_1024x1024" width="721"/></a></p> Cold solder! FYI, I have ple…tag:ehscott.ning.com,2015-01-10:3925821:Comment:462922015-01-10T00:04:37.639ZNorman S Braithwaitehttps://ehscott.ning.com/profile/NormanSBraithwaite
<p>Cold solder! FYI, I have plenty of extra diode coils if anyone finds their set to be in need.</p>
<p>Norman</p>
<p>Cold solder! FYI, I have plenty of extra diode coils if anyone finds their set to be in need.</p>
<p>Norman</p> Taking a close look for a mis…tag:ehscott.ning.com,2015-01-09:3925821:Comment:463672015-01-09T23:42:03.188ZLou deGonzaguehttps://ehscott.ning.com/profile/LoudeGonzague
<p>Taking a close look for a mis-wire I discovered no continuity to plate of 6B7. After energizing there was no plate voltage to 6b7. My fear was an open coil in the RF diode can. Turns out the 1K resistor had broken off the terminal. I was surprized to see this since it was under no stress during the rebuild. Looking at the break under magnification it was a very square separation. I tried to take a close up. It looks like it just separated from the solder joint, I made a red pointer to…</p>
<p>Taking a close look for a mis-wire I discovered no continuity to plate of 6B7. After energizing there was no plate voltage to 6b7. My fear was an open coil in the RF diode can. Turns out the 1K resistor had broken off the terminal. I was surprized to see this since it was under no stress during the rebuild. Looking at the break under magnification it was a very square separation. I tried to take a close up. It looks like it just separated from the solder joint, I made a red pointer to the spot. So it's been replaced ad now the adjustment does work. I'm glad it wasn't the coil and I didn't just dismiss the non adjust problem. Thanks to Norman and this Forum.<a target="_self" href="http://storage.ning.com/topology/rest/1.0/file/get/2771122413?profile=original"><img class="align-full" src="http://storage.ning.com/topology/rest/1.0/file/get/2771122413?profile=original" width="652"/></a><a target="_self" href="http://storage.ning.com/topology/rest/1.0/file/get/2771122503?profile=original"><img width="721" class="align-full" src="http://storage.ning.com/topology/rest/1.0/file/get/2771122503?profile=RESIZE_1024x1024" width="721"/></a></p> Can you post a sketch of how…tag:ehscott.ning.com,2015-01-09:3925821:Comment:462482015-01-09T01:38:56.217ZNorman S Braithwaitehttps://ehscott.ning.com/profile/NormanSBraithwaite
<p>Can you post a sketch of how the RF diode is wired into the circuit? There is a common restoration error that will defeat the RF diode function.</p>
<p>Norman</p>
<p>Can you post a sketch of how the RF diode is wired into the circuit? There is a common restoration error that will defeat the RF diode function.</p>
<p>Norman</p> Well, I tried that adjustment…tag:ehscott.ning.com,2015-01-08:3925821:Comment:462462015-01-08T20:48:02.526ZLou deGonzaguehttps://ehscott.ning.com/profile/LoudeGonzague
<p>Well, I tried that adjustment but there was no effect when turning the adj. screw on either the audio at the VC or the AVC line. I used a very strong signal ay the antenna at 1100 kc. I tried different levels but no change. there is a new 6B7 and 6A7 installed.</p>
<p>Well, I tried that adjustment but there was no effect when turning the adj. screw on either the audio at the VC or the AVC line. I used a very strong signal ay the antenna at 1100 kc. I tried different levels but no change. there is a new 6B7 and 6A7 installed.</p> Thanks Norman, I'll make that…tag:ehscott.ning.com,2015-01-04:3925821:Comment:458512015-01-04T12:45:03.838ZLou deGonzaguehttps://ehscott.ning.com/profile/LoudeGonzague
<p>Thanks Norman, I'll make that adjustment. i think this will be the last thing to do and I am done with the restoration.</p>
<p>Thanks Norman, I'll make that adjustment. i think this will be the last thing to do and I am done with the restoration.</p> I do not believe the circuit…tag:ehscott.ning.com,2015-01-04:3925821:Comment:459672015-01-04T06:07:40.564ZNorman S Braithwaitehttps://ehscott.ning.com/profile/NormanSBraithwaite
<p>I do not believe the circuit is considered a wave trap. It is definitely not a 465kc wave trap. It is an AVC circuit reducing RF gain on strong stations to prevent overloading the IF amplifier. The source for AVC voltage is after the converter therefore the RF AVC diode is tuned to the IF frequency but in a manner that attenuates strong RF signals rather than peaking weak signals.</p>
<p>I do not believe the circuit is considered a wave trap. It is definitely not a 465kc wave trap. It is an AVC circuit reducing RF gain on strong stations to prevent overloading the IF amplifier. The source for AVC voltage is after the converter therefore the RF AVC diode is tuned to the IF frequency but in a manner that attenuates strong RF signals rather than peaking weak signals.</p>