[Heath] Inductor Values

[Doug & Kathy Davies]

I ran the numbers through an on-line inductance calculator using the stock
Heathkit coils.  They all came out exactly what the manual values said they
should be.  I then wound a few turns of enameled wire on the form I have
and, after playing with the turns, I achieved a value of 0.318 uH.  The
manual value is 0.320 uH so I think I'm good to go with those I wound.
Looks like I won't be relying on the AADE L/C meter.

The coils are for the low pass filter in a Heathkit DX-60B transmitter.
The schematic can be viewed here: https://www.vintage-radio.info/heathkit/

Doug
VE7DRF

On Wed, Mar 7, 2018 at 9:38 AM, Doug & Kathy Davies <dkdavies3 at gmail.com>
wrote:

> I'm in the process of completing a previously partially built Heathkit
> DX-60B transmitter.  Yesterday, I was assembling the low-pass filter and
> found that two of the coil were missing.  Figuring I could wind my own, I
> got some enameled wire and wound a bunch on a form that looked to be close
> to the right diameter.  I measured the value with my AADE L/C meter and
> finding that it was too high, started to remove turns until I got to the
> correct value which was 0.32 uh in this case.  Just for grins, I put the
> meter on one of the kit-supplied "green marked" coils that was, according
> to the manual, supposed to be 0.44uh.  It measured 0.098uh. Since there are
> two of these, I measured the other one and it' value was 0.094uh.   I
> also measured the other coils and they too were not even close to the
> manual values.  Now this has me puzzled.  Why would Heath put coils in
> the kit that are way out of spec. or, does it really matter for this
> application?
>
> Doug
> VE7DRF
>
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