EXCELLENT job of covering the Command series receivers. As you noted, many new hams cut their teeth on ham radio using these receivers (I started with a BC-453 in 1970). I learned a lot about ham radio by extensively modifying it and putting it on the air. I have had an interest in restoring one of these radios. Your excellent series will help push me toward that goal. Thank You... N0GWC
Nicely done. I don't think I've seen another video that explains the ARC-5 as well as you have done here. Looking forward to the next one. 73 -- de Mick, WB4LSS
Thanks for the tip on the resistance chart. I didn't realize that it was in the manual. I just finished reviving a BC-946-B receiver which covers .55 to 1.5 MHz, the AM broadcast band. The resistance chart helped me to more quickly locate the problem, which was that R22 AND R23 were open. These resistors are used as a voltage divider to produce the screen voltage. With both of them open there was no screen voltage on any of the tubes. I tacked in a couple of replacement resistors and the radio started right up. One suggestion I have for the capacitors is to consider reforming the electrolytic capacitors (C30, C32 and C5) prior to applying power. When stored for a long time, electrolytics "depolarize". This can cause high current to flow when power is applied, destroying the caps. Electrolytic caps are reformed by limiting the charging current (< 5mA) while slowly increasing the DC voltage up to the rated voltage. MIL-HDBK-1131 describes the reforming process. This handbook is easy to find on the web. In this BC-946 C30, the 15 uf audio amp cathode bypass cap, would have been destroyed. The initial leakage current was very high but settled down to about 100 uA after a couple of hours of careful reforming. Reforming can be easier than restuffing the can. C32 and C5 would probably have been OK, their currents quickly went down to a reasonable level. None of the paper caps in this radio showed any measurable leakage, which was a pleasant surprise. Thanks for creating such a detailed, informative and interesting series on these receivers. 73 - Pat W9JI
Thanks Michael for video on command receiver resto. Your technique is spot on. My ARC R26 restoration is on my website at www.vk6fh.com/vk6fh/command%20rcvr.htm best wishes from Australia
EXCELLENT job of covering the Command series receivers. As you noted, many new hams cut their teeth on ham radio using these receivers (I started with a BC-453 in 1970). I learned a lot about ham radio by extensively modifying it and putting it on the air. I have had an interest in restoring one of these radios. Your excellent series will help push me toward that goal. Thank You... N0GWC
Nicely done. I don't think I've seen another video that explains the ARC-5 as well as you have done here. Looking forward to the next one.
73 -- de Mick, WB4LSS
Thanks for the tip on the resistance chart. I didn't realize that it was in the manual.
I just finished reviving a BC-946-B receiver which covers .55 to 1.5 MHz, the AM broadcast band. The resistance chart helped me to more quickly locate the problem, which was that R22 AND R23 were open. These resistors are used as a voltage divider to produce the screen voltage. With both of them open there was no screen voltage on any of the tubes. I tacked in a couple of replacement resistors and the radio started right up.
One suggestion I have for the capacitors is to consider reforming the electrolytic capacitors (C30, C32 and C5) prior to applying power. When stored for a long time, electrolytics "depolarize". This can cause high current to flow when power is applied, destroying the caps. Electrolytic caps are reformed by limiting the charging current (< 5mA) while slowly increasing the DC voltage up to the rated voltage. MIL-HDBK-1131 describes the reforming process. This handbook is easy to find on the web.
In this BC-946 C30, the 15 uf audio amp cathode bypass cap, would have been destroyed. The initial leakage current was very high but settled down to about 100 uA after a couple of hours of careful reforming. Reforming can be easier than restuffing the can. C32 and C5 would probably have been OK, their currents quickly went down to a reasonable level.
None of the paper caps in this radio showed any measurable leakage, which was a pleasant surprise.
Thanks for creating such a detailed, informative and interesting series on these receivers.
73 - Pat W9JI
Thanks for the information very useful information its a great series
Mr. Carlson has a capacitor checker that operates on 12 vdc.
I get scared watching him. All I think about is all of that gear coming crashing down! Hee.
Thanks Michael for video on command receiver resto.
Your technique is spot on. My ARC R26 restoration is on my website at www.vk6fh.com/vk6fh/command%20rcvr.htm
best wishes from Australia