Re: [Repeater-Builder] 12vdc or 120vac Fan?
I would go with the 120. 12volt fans have a bad habit of dirtying the DC voltage which can ocasionally be heard in the repeaters audio. On Fri, 18 Mar 2005 21:23:04 -, kc4wgh [EMAIL PROTECTED] wrote: Which fan would be better on the GE MastrII, and Motorola Micor mobile radio converted into a repeater; 12vdc or 120vac? Thanks in advance. Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] 12vdc or 120vac Fan?
At 3/18/2005 01:23 PM, you wrote: Which fan would be better on the GE MastrII, and Motorola Micor mobile radio converted into a repeater; 12vdc or 120vac? Thanks in advance. The radio doesn't care, but if you're going to switch the fans with PTT or thermally, it'll be easier with 12 V. Also don't have to worry about cooling if running on emergency battery power. Bob NO6B Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] 12vdc or 120vac Fan?
At 02:32 PM 3/18/2005 -0700, you wrote: I would go with the 120. 12volt fans have a bad habit of dirtying the DC voltage which can ocasionally be heard in the repeaters audio. --Not with proper filtering it doesn't. Besides, I believe that most 12 volt fans use less power than their 120 Vdc counterparts. Ken Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] 12vdc or 120vac Fan?
At 01:23 PM 3/18/05, you wrote: Which fan would be better on the GE MastrII, and Motorola Micor mobile radio converted into a repeater; 12vdc or 120vac? Thanks in advance. Is your system going to go away if the 120v goes away? If yes, then 120v AC fans are usable. If you are going to use the battery backup facility in the Micor, then you will need cooling while on batteries and that means 12v DC fans. If you need fans at all - many Micor stations are convection cooled, and only need the fans if you run them continuous duty (i.e. lock to talk mode). Some folks will tell you that the 12v fans can put noise on the DC supply and thereby on the TX audio. This is true, but only if the TX audio circuits aren't filtered properly, and if the fans aren't filtered properly. You will need to put a filter on the fans, and the average fan takes much less than a quarter amp usually less wattage then the equivalent AC fan. Building up a filter for a few fans is trivial - a couple hundred UFs and an old transformer winding used as a choke. Run the DC to the choke, then the caps to ground. Put the fans in parallel with the cap. All of the audio circuits should be fed by their own filtered DC power... should be immune to noise on the DC supply line. If the fans are audible in the TX audio you need to properly filter the TX audio circuits first, then add filtering to the fans as well so that if one filter breaks the system is still clean. There is no excuse for half-engineered systems. Phil Lefever, KB0NES made the point quite well in an email posting when he said: I hate driving up the hill to fix something I could have done better the first time around. Mike Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] 12vdc or 120vac Fan?
With proper filtering the 12 volt fans would be fine. I have two 4" 12 VDC fans on my PA and have no audio issues at all. They are noisy as all get out in the repeater room, but cannot be detected on the repeater. Mathew DCFluX [EMAIL PROTECTED] wrote: I would go with the 120. 12volt fans have a bad habit of dirtying theDC voltage which can ocasionally be heard in the repeaters audio.On Fri, 18 Mar 2005 21:23:04 -, kc4wgh <[EMAIL PROTECTED]>wrote: Which fan would be better on the GE MastrII, and Motorola Micor mobile radio converted into a repeater; 12vdc or 120vac? Thanks in advance. Yahoo! Groups LinksYahoo! Groups Links* To visit your group on the web, go to:http://groups.yahoo.com/group/Repeater-Builder/* To unsubscribe from this group, send an email to:[EMAIL PROTECTED]* Your use of Yahoo! Groups is subject to:http://docs.yahoo.com/info/terms/ Do you Yahoo!? Yahoo! Small Business - Try our new resources site! Yahoo! Groups Links To visit your group on the web, go to:http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
Re: [Repeater-Builder] 12vdc or 120vac Fan?
Had the noisy problem in one of my repeaters, 3 to 5 ohms 4 watts resistor in series with positive line and a 1000mfd/16volts in the fan side cured 100%. Juan - Original Message - From: DCFluX To: Repeater-Builder@yahoogroups.com Sent: Friday, March 18, 2005 1:32 PM Subject: Re: [Repeater-Builder] 12vdc or 120vac Fan? I would go with the 120. 12volt fans have a bad habit of dirtying theDC voltage which can ocasionally be heard in the repeaters audio.On Fri, 18 Mar 2005 21:23:04 -, kc4wgh [EMAIL PROTECTED] wrote: Which fan would be better on the GE MastrII, and Motorola Micor mobile radio converted into a repeater; 12vdc or 120vac? Thanks in advance. Yahoo! Groups Links Yahoo! Groups Links* To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/* To unsubscribe from this group, send an email to: [EMAIL PROTECTED]* Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/ Yahoo! Groups Links To visit your group on the web, go to:http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
Re: [Repeater-Builder] 12vdc or 120vac Fan?
kc4wgh wrote: Which fan would be better on the GE MastrII, and Motorola Micor mobile radio converted into a repeater; 12vdc or 120vac? Thanks in advance. A 240 VAC muffin fan run on 120 VAC is best. Second best is a 120 VAC. Third, 12 VDC run from a separate supply. Fourth, 12 VDC run from the main supply with chokes and caps to keep the noise off the B+ line. Kevin Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
