Chuck, you wrote:
>The circuit diagram published in the last QRPp for the Rainbow
>Tuner shows R5 to be 51 ohms. The Parts List in the article
>lists this as 10K, which is probably the correct value, since the
>circuit shows C2+R5+C4 as being in parallel across R2 in the
>comparison leg of the bridge. Since R5 is shown as 51 ohms, the
>series combination of C2+R5+C4 would be around 51 ohms (at, say,
>10MHz) and the impedance against which the antenna would be
>compared would be more like 26 ohms, rather than 51 ohms. If
>working from the article, please note the disagreement between
>the diagram and the Parts List.
In short, you are right, I made a typo on the schematic diagram that was
printed in the article. R5 is indeed, 10 k ohms and is simply a decoupling
resistor for the rectified sample.
I wish that were the only typo in the article! In fact, if you compare the
one printed in QRPp with the one printed in the QRP Quarterly, the typos
should match :-)
I've had several queries on the typos and I *do* ahve a list of them. Now
that the Rainbow manual is finally done, I should be able to find time this
week to post them all on qrp-l.
At least I know that you were interested enough to read it carefully!
If you respond to this, please do so to my home e-mail address
72/73,
joe E., N2CX
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