[amsat-bb] Re: Arrow 10W Duplexer Performance Measurements
mat_62 at netcommander.com
Wed Oct 21 14:00:14 PDT 2009
Funny this should come up. I was doing some research on what kind of
luck folks had with Ramsey preamps and came upon this link...
I don't think this guys application used a diplexer and my 70cm antenna
will be strictly receive as well but this struck me as kind of what you
were talking about doing with the ARR unit.
Bruce Robertson wrote:
> I'm grateful to everyone who has contributed to this discussion.
> It strikes me that the greatest improvement we could make to hand-held
> yagis would be to somehow integrate a low noise preamp circuit very
> close to the 70cm port. I have an indoor-style ARR preamp that I've
> thought of connecting to the boom with cable ties. A powersupply using
> AA batteries and a DC to DC buck-boost chip from, e.g., Maxim, would
> keep the whole thing light. (Alternatively, I see that the max voltage
> for my ARR is pretty high: I might get away with a pair of Nicad '9v'
> Like so much of amateur radio, it's more of a challenge of
> construction than anything else.
> Has anyone experimented with this sort of improvement?
> 73, VE9QRP
> On Wed, Oct 21, 2009 at 8:21 AM, Allan Saul <allan at rfdesign.co.za> wrote:
>> Quite a lot of guys are using the handy Arrow Model 10W
>> duplexer for the handheld 146/437 antenna and mine arrived here
>> today so I thought I would put it on the network analyser
>> and see how it performs.....
>> >From the Radio cable to the 2m antenna connector an Insertion Loss of
>> 0.75dB was measured with a rejection of 57dB at 70cm. The VSWR at 2m was
>> >From the Radio cable to the 70cm antenna connector an Insertion Loss of
>> 1.2dB was measured with an attenuation of 56dB on the 2m signal. The VSWR
>> at 70cm was 1.29:1
>> The VSWR on the 2m port was 1.21:1 and on the 70cm port was 1.20:1
>> For those guys wanting to look at the actual plots they can be found here
>> Allan ZS1LS
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