Eric, The power supply on the RKR and GR series repeaters has a switch which controls the action of the fan. It can either be thermally controlled or run constantly.
Milt N3LTQ ----- Original Message ----- From: "Eric Lemmon" <[email protected]> To: <[email protected]> Sent: Saturday, May 01, 2010 11:04 PM Subject: RE: [Repeater-Builder] Neat kit for switching repeater devices > Larry, > > That's odd; both the GR1225 and RKR1225 repeaters I am familiar with, > which > use the R1225 transceiver, have a small thermal switch that is wedged > between two of the heat-sink fins. In both repeaters, the fan runs only > when the radio gets hot. I am surprised that you have a repeater using > the > R1225 in which the fan runs continuously. Perhaps this installation is a > prime candidate for a thermal switch! > > 73, Eric Lemmon WB6FLY > > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Larry Horlick > Sent: Saturday, May 01, 2010 7:13 PM > To: [email protected] > Subject: Re: [Repeater-Builder] Neat kit for switching repeater devices > > > > This is excellent Eric. I have an R1225 repeater in a GR500 case. There is > a > fan but it runs continuously. The duty cycle is low but because of the > nature of > the service there are times when it may be very high for extended periods > of > time. > So most of the time the fan is not needed, but I want it there for those > rare occasions. > I don't recognize the part no. on the fan it looks remarkably similar to > the > one stock in > GR500. This will work very well for me. Thanks. > > lh > > On Sat, May 1, 2010 at 8:28 PM, Eric Lemmon <[email protected] > <mailto:[email protected]> > wrote: > > > > > Larry, > > My first use of this thermal switch was on a solar-powered Motorola > R1225 > UHF repeater at a commercial site. I simply drilled and tapped two > 4-40 > holes on a flat portion of the outside fin, and mounted the thermal > switch > after applying some heat-conductive paste. I used a three-inch > low-EMI > Panasonic fan blowing right on the fins. This is a 45-watt repeater > set for > about 30 watts output. It went into service early in 2003, and has > been > trouble-free ever since. I have attached a picture of what it looks > like. > > 73, Eric Lemmon WB6FLY > > -----Original Message----- > From: [email protected] > <mailto:Repeater-Builder%40yahoogroups.com> > [mailto:[email protected] > <mailto:Repeater-Builder%40yahoogroups.com> ] On Behalf Of Larry Horlick > Sent: Saturday, May 01, 2010 11:56 AM > To: [email protected] > <mailto:Repeater-Builder%40yahoogroups.com> > Subject: Re: [Repeater-Builder] Neat kit for switching repeater > devices > > Eric, > > This is good info. I have an immediate use for this. How have you > actually > attached this 'stat to the fin? > > Larry > > On Sat, May 1, 2010 at 2:36 PM, Eric Lemmon <[email protected] > <mailto:wb6fly%40verizon.net> > <mailto:[email protected] <mailto:wb6fly%40verizon.net> > > wrote: > > > > Scott, > > I must agree that the CK1614 is an extremely versatile timer, with > many > potential uses. However, using it for fan control is not only > expensive, > but unnecessary. > > A fan blowing on a transmitter heat sink does absolutely nothing > immediately > after the transmitter is keyed, since the heat sink is likely at > ambient > temperature. It takes a period of time for the heat sink to warm up, > so > operating the fan prematurely is a waste of energy- which may be an > issue > for a solar-powered repeater. > > IMHO, the most efficient means of fan control is also the cheapest: > A > thermal switch. My first choice is a Cantherm #R2005015 > normally-open > thermostat that closes at 50 degrees Celsius, about 122 degrees > Fahrenheit. > When attached to a heat-sink fin, it turns the fan on when > necessary, and > keeps it on until the heat sink cools below about 100 degrees F- > around body > temperature. This particular switch is available from Digi-Key for > about > $9, as Catalog Number 317-1094-ND. > > 73, Eric Lemmon WB6FLY > > > -----Original Message----- > From: [email protected] > <mailto:Repeater-Builder%40yahoogroups.com> > <mailto:Repeater-Builder%40yahoogroups.com > <mailto:Repeater-Builder%2540yahoogroups.com> > > [mailto:[email protected] > <mailto:Repeater-Builder%40yahoogroups.com> > <mailto:Repeater-Builder%40yahoogroups.com > <mailto:Repeater-Builder%2540yahoogroups.com> > ] On Behalf Of na4it > Sent: Saturday, May 01, 2010 9:38 AM > To: [email protected] > <mailto:Repeater-Builder%40yahoogroups.com> > <mailto:Repeater-Builder%40yahoogroups.com > <mailto:Repeater-Builder%2540yahoogroups.com> > > Subject: [Repeater-Builder] Neat kit for switching repeater devices > > I have started using this little kit > (http://www.electronickits.com/kit/complete/elec/ck1614.htm > <http://www.electronickits.com/kit/complete/elec/ck1614.htm> > <http://www.electronickits.com/kit/complete/elec/ck1614.htm > <http://www.electronickits.com/kit/complete/elec/ck1614.htm> > > <http://www.electronickits.com/kit/complete/elec/ck1614.htm > <http://www.electronickits.com/kit/complete/elec/ck1614.htm> > <http://www.electronickits.com/kit/complete/elec/ck1614.htm > <http://www.electronickits.com/kit/complete/elec/ck1614.htm> > > ) for fan > control on repeaters. I can also be used as a PTT and Time Out > circuit, > along with a lot of other uses. > > Download the pdf on that site and check it out. > > Scott NA4IT > > > > > > > > > > > ------------------------------------ > > > > Yahoo! Groups Links > > >
