[Elecraft] A comment about Receiving

[Dale Parfitt]

How does the preselector know to peak up the RX signal and not also peak up 
the noise?

Dale W4OP

> Rich,
>
> Yes the tuner acts as a preselector and peaks up the signal.
>
> Years ago I wrote W6AM a letter asking him if he used an antenna tuner
> with his rhombic antennas.  He replied that he did use a tuner but not so 
> much
> to improve the impedance match to the rhombics for transmit, (he had them 
> tuned up pretty well)
> but to act as a preselector to peak up the signals.  He went on to 
> describe his
> setup, using Collins 75A4 receivers and a Johnson KW matchboxes.  He said 
> the
> big Johnson KW matchbox, not the smaller one, was very effective at 
> peaking up the
> received signal.  I was convinced that the tuner was a a good thing to 
> have in line
> for receive if he had receive enhancement using the tuner with his big 
> rhombics !
>
>
> Bob
> K6UJ
>
>
>
> On Mar 28, 2011, at 11:05 AM, Richard Fjeld wrote:
>
>> For me, receive capability was an important factor, among others, in the 
>> decision to buy an Elecraft. The model is irrelevant to this post. For 
>> years, I have been studying comments made about receiving, as opposed to 
>> those who think a radio is 'good to the last watt'. Recently, there was a 
>> rather lengthy thread about whether a K3 user was having receive problems 
>> or not.  I'd like to share an experience with the group.
>>
>> Over the years, I have used coax fed antennas and lived with compromise 
>> SWR figures. I wanted an all-band antenna so I recently changed the 80 
>> meter dipole so that it is center fed with homebrew 450 ohm ladder-line 
>> to a tuner. I use an MFJ Matchmaker (TM) to 'tune the tuner'.  While it 
>> puts out a white noise, I tune for minimum S-meter reading. When 
>> finished, a quick transmit reveals the SWR.
>>
>> One day while tuning close to optimum at the frequency I was on, and 
>> because I receive while I tune, I began to hear a weak CW signal. At 
>> first, I thought it had just come on frequency, but as I listened, I 
>> realized that the station had been in qso for awhile, but I didn't hear 
>> it until I reached optimum resonance with the tuner. I knew a resonant 
>> antenna was important, but I was surprised at the difference it could 
>> make in receiving. A good receiver is wasted if the signal doesn't get to 
>> it.
>>
>>
>> Richard Fjeld, n0ce
>> rpfjeld at embarqmail.com
>> I'd rather be learning.
>>
>>
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