You are unfortunately correct and this was not clear in any manuals, at least to me, when I began to use an icom preamp for 435 on my TS-2000. Hence, a blown preamp! There is a guy I found on eBay that sells a switching box that plugs into the external control port on a TS-2000 and gives you a relay control RCA out cable for each of the VHF/UHF bands, even 1.2 if you have it. You can control either amps or preamps. I may look into this, once I figure out how to repair the preamp if it is even repairable, but I think it is. Thanks for all the input everyone. At the end of the day I wish I had my 847 as I feel it may be a more user friendly rig for sats at least for controlling external preamps. Rick W2JAZ
Sent from my iPad http://RickLawn.com On Aug 12, 2012, at 8:39 AM, "Mark L. Hammond" <[email protected]> wrote: > Hi All, > > Somebody please clarify---I may be wrong, but I thought the Icom preamps did > the following with Icom radios: > > In receive, 12V is powered up the coax. Device is powered, preamp is ON. > In transmit, the 12 power feed is stopped. Device is not powered, and it's > bypassed during xmit. > > If this is the case, it complicates greatly the use of Icom preamps on > non-Icom radios (means there isn't a typical RF-sensed bypass circuit, which > means it would be easy to blow in a non-Icom radio). > > Am I remembering this wrong? > > Mark N8MH > > At 09:30 PM 8/11/2012 -0700, Art McBride wrote: >> Rick, >> I suggest you use a VOM or DMM to measure the current drawn on 12 volts >> going to the power injector. If everything is connected correctly It will >> draw 30-200 mA. Confirm that you have continuity in your coax. Some >> lightning arrestors have a DC block built in. It is best to test it with a >> short run of coax between the preamp and the power injector at the radio >> while listening to a local repeater to see if the signal increases when you >> apply power to it. If it operates then you can proceed to determine if there >> are problems with the coax to the antenna, not carrying the 12 VDC. >> 73 >> Art, >> KC6UQH >> >> -----Original Message----- >> From: [email protected] [mailto:[email protected]] On >> Behalf Of Lawn, Richard >> Sent: Saturday, August 11, 2012 3:30 PM >> To: [email protected] >> Subject: [amsat-bb] Icom AG-35 Preamp Question >> >> I bought an Icom AG-35 preamp about a year ago. The fellow ham advertised it >> as virtually brand new and it was/is. I planned to use it this summer with a >> TS-2000 which doesn't supply 12v voltage to the coax to power a preamp as >> other xcvrs do. I used a Mirage KP2 unit to inject power to the coax to >> drive mast mounted the preamp. When I turn the power on there seems to be >> little or no noticeable difference in background noise and worse than that I >> cannot here any signals on FO-29 downlink, and I know the bird has been >> active. Any suggestions? Is the preamp fried? I can't even get the weather >> proof case off to trouble shoot, not that I'd know what to look for. Any >> suggestions on repair? >> >> TNX >> 73 >> Rick >> W2JAZ >> >> >> _______________________________________________ >> Sent via [email protected]. Opinions expressed are those of the author. >> Not an AMSAT-NA member? Join now to support the amateur satellite program! >> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb >> >> _______________________________________________ >> Sent via [email protected]. Opinions expressed are those of the author. >> Not an AMSAT-NA member? Join now to support the amateur satellite program! >> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb > _______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
