- 1. [AMPS] SB-220 C4 failure (score: 1)
- Author: W7OM@aol.com (W7OM@aol.com)
- Date: Sat, 5 Jul 1997 14:11:43 -0400 (EDT)
- The 20 mfd electrolytic cap in the 120 vdc power supply ruptured. This failure occurred with a possible tube short. Do not believe there is a correlation. Replacement is simple, BUT would like to kno
- /archives//html/Amps/1997-07/msg00007.html (8,067 bytes)
- 2. [AMPS] SB-220 C4 failure (score: 1)
- Author: wrt@eskimo.com (Bill Turner)
- Date: Sat, 05 Jul 1997 19:48:49 GMT
- <><><><><><><><><><><><><><><><><><><><><><><><><><><><> In my 38 years of electronics, it's been my experience that solid-state diodes never short and then repair themselves. If it checks good, it i
- /archives//html/Amps/1997-07/msg00008.html (8,792 bytes)
- 3. [AMPS] SB-220 C4 failure (score: 1)
- Author: measures@vc.net (Rich Measures)
- Date: Sun, 6 Jul 97 02:50:05 -0700
- - I agree, Bill Rich-- R. L. Measures, 805-386-3734, AG6K -- FAQ on WWW: http://www.contesting.com/ampfaq.html Submissions: amps@contesting.com Administrative requests: amps-REQUEST@contesting.com P
- /archives//html/Amps/1997-07/msg00009.html (9,159 bytes)
- 4. [AMPS] SB-220 C4 failure (score: 1)
- Author: km1h@juno.com (u nut)
- Date: Sun, 06 Jul 1997 10:01:06 EDT
- After 25+ years that capacitor has a history of going bad. Simply replace it. I replace it as a mater of course whenever I get a SB-220 in for service. 73...Carl KM1H -- FAQ on WWW: http://www.contes
- /archives//html/Amps/1997-07/msg00010.html (9,191 bytes)
- 5. [AMPS] SB-220 C4 failure (score: 1)
- Author: measures@vc.net (Rich Measures)
- Date: Sun, 6 Jul 97 08:36:33 -0700
- 25 years is pretty typical for the life span of 85º C-rated electrolytics. For even longer life, a 105ºC-rated electrolytic would be appropriate. I would be inclined to covert the mickeymo
- /archives//html/Amps/1997-07/msg00011.html (8,590 bytes)
- 6. [AMPS] SB-220 C4 failure (score: 1)
- Author: km1h@juno.com (km1h @ juno.com)
- Date: Sun, 06 Jul 1997 20:07:59 EDT
- I believe the early originals were 65C rated (old brown wrapper) and later 221's used a blue 85C which I have yet to see go bad. I simply use 22MF/160V 85C from Mouser...they will outlast the owner.
- /archives//html/Amps/1997-07/msg00014.html (9,370 bytes)
- 7. [AMPS] SB-220 C4 failure (score: 1)
- Author: measures@vc.net (Rich Measures)
- Date: Sun, 6 Jul 97 19:40:19 -0700
- - ok, so the option keys don't work on this server. For adding a step-start relay and high speed switching, a FWB is indicated. Half-wave rectification causes DC to unhappily flow in the transformer
- /archives//html/Amps/1997-07/msg00016.html (9,919 bytes)
- 8. [AMPS] SB-220 C4 failure (score: 1)
- Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net)
- Date: Mon, 7 Jul 1997 08:04:55 +0000
- The very small power demand of the bias supply (about 12 watts) would not greatly affect the core losses of a transformer already delivering 160 watts to a resistive load. The half wave rectifier is
- /archives//html/Amps/1997-07/msg00017.html (9,493 bytes)
- 9. [AMPS] SB-220 C4 failure (score: 1)
- Author: km1h@juno.com (km1h @ juno.com)
- Date: Mon, 07 Jul 1997 10:06:12 EDT
- IMO, adding Step-Start to the SB-220 is a complete waste of time and money. The filament xfmr was designed to limit inrush current. The plate xfmr is also current limited. The power supply has other
- /archives//html/Amps/1997-07/msg00018.html (10,286 bytes)
- 10. [AMPS] SB-220 C4 failure (score: 1)
- Author: measures@vc.net (Rich Measures)
- Date: Mon, 7 Jul 97 11:06:57 -0700
- ...snip... - The HV transformer is required to produce repetitive, high peak currents to satisfy the considerable demand of the C-filter. If the HV transformer were designed to limit current--like t
- /archives//html/Amps/1997-07/msg00020.html (10,168 bytes)
- 11. [AMPS] SB-220 C4 failure (score: 1)
- Author: km1h@juno.com (km1h @ juno.com)
- Date: Mon, 07 Jul 1997 17:03:28 EDT
- I did not say that the xfmr was designed to limit current, I said it was current limited....there is a big difference between the two. Possibly, but I suspect the majority of On-OFF switch failures a
- /archives//html/Amps/1997-07/msg00022.html (10,596 bytes)
- 12. [AMPS] SB-220 C4 failure (score: 1)
- Author: wrt@eskimo.com (Bill Turner)
- Date: Mon, 07 Jul 1997 23:54:33 GMT
- On Mon, 07 Jul 1997 17:03:28 EDT, km1h@juno.com (km1h @ juno.com) wrote: <snip> <><><><><><><><><><><><><><><><><><><><><><><><><><><><> Could you elaborate on that please? Thanks. 73, Bill W7TI -- F
- /archives//html/Amps/1997-07/msg00024.html (9,417 bytes)
- 13. [AMPS] SB-220 C4 failure (score: 1)
- Author: measures@vc.net (Rich Measures)
- Date: Mon, 7 Jul 97 22:30:12 -0700
- ...and the big difference is? Rich-- R. L. Measures, 805-386-3734, AG6K -- FAQ on WWW: http://www.contesting.com/ampfaq.html Submissions: amps@contesting.com Administrative requests: amps-REQUEST@co
- /archives//html/Amps/1997-07/msg00025.html (9,676 bytes)
- 14. [AMPS] SB-220 C4 failure (score: 1)
- Author: measures@vc.net (Rich Measures)
- Date: Mon, 7 Jul 97 22:30:17 -0700
- - 20uF in half-wave service is perfectly fine for filtering the original 20mA load, however, it is a bit lacking for filtering the 100mA that the high speed switching and step-start circuits consume
- /archives//html/Amps/1997-07/msg00026.html (9,796 bytes)
- 15. [AMPS] SB-220 C4 failure (score: 1)
- Author: km1h@juno.com (km1h @ juno.com)
- Date: Tue, 08 Jul 1997 08:41:48 EDT
- Rich, Bill, etc The big difference is the word "designed". I dont believe that the Heath engineers were overly concerned about PS inrush current. It wasnt a marketing hype word back then. The SB-220
- /archives//html/Amps/1997-07/msg00027.html (10,726 bytes)
- 16. [AMPS] SB-220 C4 failure (score: 1)
- Author: km1h@juno.com (km1h @ juno.com)
- Date: Tue, 08 Jul 1997 08:41:49 EDT
- True, but the original discussion was about the capacitor failing and requiring replacement anyway. The cost of a 100-200MF 160V capacitor, if someone wants to add a bunch of extra parts will not req
- /archives//html/Amps/1997-07/msg00028.html (10,923 bytes)
- 17. [AMPS] SB-220 C4 failure (score: 1)
- Author: measures@vc.net (Rich Measures)
- Date: Tue, 8 Jul 97 07:09:16 -0700
- With half-wave rectification, a 100mA winding is not good for 100mA DC. With full-wave bridge rectification, it pretty much is. We are not talking about QSK operators, Carl. A 5mS QSK radio starts d
- /archives//html/Amps/1997-07/msg00030.html (11,182 bytes)
- 18. [AMPS] SB-220 C4 failure (score: 1)
- Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net)
- Date: Tue, 8 Jul 1997 20:48:06 +0000
- To: <amps@contesting.com> That's correct Carl. Inrush was never a part of the concern. It wasn't until 1970 or so that inrush became the curse of the 220, causing arcs and pops and snaps and blowing
- /archives//html/Amps/1997-07/msg00032.html (10,293 bytes)
- 19. [AMPS] SB-220 C4 failure (score: 1)
- Author: measures@vc.net (Rich Measures)
- Date: Tue, 8 Jul 97 19:06:09 -0700
- To: <amps@contesting.com> What curse? Says who? Those who measured the SB-220's filament inrush current know that it is only 60% of what Eimac allows, thanks to Heath's special current-limiting fila
- /archives//html/Amps/1997-07/msg00033.html (10,822 bytes)
- 20. [AMPS] SB-220 C4 failure (score: 1)
- Author: w8jitom@postoffice.worldnet.att.net (w8jitom@postoffice.worldnet.att.net)
- Date: Wed, 9 Jul 1997 09:03:15 +0000
- To: <amps@contesting.com> Rich replied: Really? Doesn't the TL-922 use a series filament string?? I worked for Heath, and was involved in modernization of the SB-220 series. That made all engineerin
- /archives//html/Amps/1997-07/msg00036.html (11,373 bytes)
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