I agree on the possibility of some line loss to the unit. The longer the coax run the more problems you may have with it properly switching. I found this to be especially true of the early models of the Mirage mast mounted preamps. Even the power "T" can be a problem if the wire run is long. Presently, I am using my unit on the IC-910 without any problems, but the coax run is less than 50' of 9913. I would recommend holding onto the KP-2 for awhile. If the rig is border lined with the output voltage being around 12 volts instead of around 13.8 volts, there could be enough loss (even .5 volts) can cause erratic operation. Using the KP-2 allows you to use a separate voltage allowing sufficient amount to the preamp.
Reid, W4UPD
On 8/9/2011 7:41 PM, Sebastian, W4AS wrote:
My thanks to everyone who has responded. 4 out of 4 say it's ok to use the 847 to power the preamp.
I put up the 432 one today, but with the KP2 control box, just in case. But I will go ahead and remove the box, and let the 847 power it.
One interesting response was to be careful if there is anything inline between the rig and preamp. Lightning protection, or even an SWR power meter, could affect the sending of voltage.
73 de Sebastian, W4AS
On Aug 9, 2011, at 3:16 PM, Lowell White wrote:
Hi Sebastian,
I'll be interested in knowing that also... thanks for asking. I also have an FT-847 in my stable and have the KP2/2m on my "soon to acquire" list.
73,
Lowell K9LDW
------ Original Message ------ Received: Tue, 09 Aug 2011 11:34:22 AM CDT From: "Sebastian, W4AS"w4as@bellsouth.net To: AMSAT-BBamsat-bb@amsat.org Subject: [amsat-bb] Mirage preamps
Before I destroy these, is anyone using Mirage KP-2 mast mounted preamps
with a Yaesu FT-847?
I picked up a couple of them recently, and they came with the control box
(which appears to be a bias tee) that supplies 12 volts via the coax line, in order to power them.
The FT-847 can already supply 12 volts up the coax to mast mounted preamps;
but I wonder if these Mirage preamps require the use of the control box for some reason. I would prefer to use the rig to power the preamps, but the manual doesn't mention that option.
73 de Sebastian, W4AS
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Sent via AMSAT-BB@amsat.org. 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