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#1
February 2nd 05, 03:43 PM
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R8B and external power supply
A while back I decided to run my R8B off an external power supply. I
can't say my decision to do this was based on any very sound reasoning. I'd read some old posts in rrr about how keeping heat out of the case would promote the long term health of the receiver and, being a little paranoid about protecting my investment, I decided to go with an external supply (despite the fact that the R8B really doesn't get very warm when running off its own internal supply). My guess is that that there's no real need to use an external supply and that my desire to protect my investment made me a sucker... In any case, I've tried a couple of external power supplies, most recently a 13.8 VDC / 3amp supply from Radio Shack, and both of them introduced at least some kind of noise or hash into my reception. It was often very subtle, but enough to be a real problem when it comes to weak signals. When the R8B is running off its own internal supply, it's much quieter. It seems to like it's own, internal supply. So my question is, should just I forget about using an external supply? Thanks in advance! Steve |
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#3
February 2nd 05, 04:29 PM
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I use an Astron SS-18, which is a switching supply (so it runs fairly cool),
and is not too noisy birdie-wise. I tried a MFJ switching supply first (birdies all over) and an Astron non-switching supply (quiet but hot). It keeps the R8B much cooler, and you can stack other stuff on it because it no longer needs airflow. I much prefer it on the external supply, but the real reason for getting it was to run a couple dozen 12v accessories like active antennas and ANC-4's and DSP's as well, without having a rats' nest of wall warts. I have the SS-18 in a discarded refrigerator in the basement, far from portables lying around that might hear its birdies, and the R8B is on an external antenna so doesn't hear it in any case. Be sure to inline-fuse the power from an external supply for the cable you're using, amp-wise. Those things can burn up wire well before they reach their rated capacity, and most wire won't handle 18 amps. Slo-blo fuses run very hot, incidentally; use fast-blow fuses. -- Ron Hardin On the internet, nobody knows you're a jerk. |
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#4
February 2nd 05, 04:47 PM
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wrote A while back I decided to run my R8B off an external power supply. I can't say my decision to do this was based on any very sound reasoning. I'd read some old posts in rrr about how keeping heat out of the case would promote the long term health of the receiver and, being a little paranoid about protecting my investment, I decided to go with an external supply (despite the fact that the R8B really doesn't get very warm when running off its own internal supply). My guess is that that there's no real need to use an external supply and that my desire to protect my investment made me a sucker... In any case, I've tried a couple of external power supplies, most recently a 13.8 VDC / 3amp supply from Radio Shack, and both of them introduced at least some kind of noise or hash into my reception. It was often very subtle, but enough to be a real problem when it comes to weak signals. When the R8B is running off its own internal supply, it's much quieter. It seems to like it's own, internal supply. So my question is, should just I forget about using an external supply? Thanks in advance! Steve Heat is an enemy of all electronics, and even though the R8B does run cooler than any other receiver I own, it could improve frequency stability to run it even cooler from a DC pwr supply. Btw I also use a RS 3a regulated pwr supply (to run an ATU) and except for the spike of turning it on/off, have never noticed any hash on receivers from it. Jack |
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#6
February 2nd 05, 08:01 PM
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Get a piece of cardboard or a piece of thin wood paneling and push a lot
of long thumbtacks into the cardboard or panel and set the panel on top of your radio(s) tv sets or whatever with the points of the thumbtacks pointing up.That should keep the cats off. cuhulin |
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#7
February 3rd 05, 05:35 AM
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Jack Painter wrote:
wrote A while back I decided to run my R8B off an external power supply. I can't say my decision to do this was based on any very sound reasoning. I'd read some old posts in rrr about how keeping heat out of the case would promote the long term health of the receiver and, being a little paranoid about protecting my investment, I decided to go with an external supply (despite the fact that the R8B really doesn't get very warm when running off its own internal supply). My guess is that that there's no real need to use an external supply and that my desire to protect my investment made me a sucker... In any case, I've tried a couple of external power supplies, most recently a 13.8 VDC / 3amp supply from Radio Shack, and both of them introduced at least some kind of noise or hash into my reception. It was often very subtle, but enough to be a real problem when it comes to weak signals. When the R8B is running off its own internal supply, it's much quieter. It seems to like it's own, internal supply. So my question is, should just I forget about using an external supply? Thanks in advance! Steve Heat is an enemy of all electronics, and even though the R8B does run cooler than any other receiver I own, it could improve frequency stability to run it even cooler from a DC pwr supply. Btw I also use a RS 3a regulated pwr supply (to run an ATU) and except for the spike of turning it on/off, have never noticed any hash on receivers from it. I use a garden variety (Radio Shack) 12V power supply. It does make a significant improvement in lowering the case temperature but it's hard to say if this will extend the componant life over the long run. I tend to think it will, so that's why I do it. There is one down side to the external DC supply though. When the internal supply is used, the clock is sync'd to the AC 60-HZ frequency which makes it more accurate than with the DC supply. ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
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#8
February 3rd 05, 05:37 AM
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"Mark S. Holden" wrote:
wrote: A while back I decided to run my R8B off an external power supply. I can't say my decision to do this was based on any very sound reasoning. I'd read some old posts in rrr about how keeping heat out of the case would promote the long term health of the receiver and, being a little paranoid about protecting my investment, I decided to go with an external supply (despite the fact that the R8B really doesn't get very warm when running off its own internal supply). My guess is that that there's no real need to use an external supply and that my desire to protect my investment made me a sucker... In any case, I've tried a couple of external power supplies, most recently a 13.8 VDC / 3amp supply from Radio Shack, and both of them introduced at least some kind of noise or hash into my reception. It was often very subtle, but enough to be a real problem when it comes to weak signals. When the R8B is running off its own internal supply, it's much quieter. It seems to like it's own, internal supply. So my question is, should just I forget about using an external supply? Thanks in advance! Steve My R8 ran "warm" on the built in power supply, and this made the top of the radio a favorite snoozing spot for our cats. Having a cat snoozing on top makes it run warmer. Without the snoozing cats problem, I'd consider an external power supply to be a belt and suspenders kind of thing. You don't need to do it, but it may prolong the life of components. Besides heat, the other problem with cats snoozing on your radios is eventually, they decide the tuning knob must be a toy since you seem to enjoy turning it. I've pretty much decided to sell my Applied Communications (Norlin) SR-2150 wideband because one of the cats is afraid of the cooling fan, and another thinks turning the tuning knob is a game. There's also the possibility of cat hair getting inside and interfering with the air circulation. ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
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#9
February 3rd 05, 09:28 AM
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starman wrote:
to think it will, so that's why I do it. There is one down side to the external DC supply though. When the internal supply is used, the clock is sync'd to the AC 60-HZ frequency which makes it more accurate than with the DC supply. Are you sure it's sync'd? My impression was that it worked off DC in either case. -- Ron Hardin On the internet, nobody knows you're a jerk. |
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#10
February 5th 05, 06:05 PM
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Ron Hardin wrote:
starman wrote: to think it will, so that's why I do it. There is one down side to the external DC supply though. When the internal supply is used, the clock is sync'd to the AC 60-HZ frequency which makes it more accurate than with the DC supply. Are you sure it's sync'd? My impression was that it worked off DC in either case. The clock circuit uses DC for the active componants but there is a connection through a capacitor to the AC line to a pin on the clock chip to sync' it. ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
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