<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:12pt"><div><span>Heath used circuit breakers in a number of different products including the HP-23A, HP-23B, and HP-23C.</span></div><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span><br></span></div><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span>As for technical specifications, there are different requirements for the older equipment. 47 CFR Part 97 Section 97.307 subparts read as follows:</span></div><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: HelveticaNeue, 'Helvetica Neue',
Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span><br></span></div><div>(d) For transmitters installed after January 1, 2003, the mean power of any spurious emission from a station transmitter or external RF power amplifier transmitting on a frequency below 30 MHz must be at least 43 dB below the mean power of the fundamental emission. For transmitters installed on or before January 1, 2003, the mean power of any spurious emission from a station transmitter or external RF power amplifier transmitting on a frequency below 30 MHz must not exceed 50 mW and must be at least 40 dB below the mean power of the fundamental emission. For a transmitter of mean power less than 5 W installed on or before January 1, 2003, the attenuation must be at least 30 dB. A transmitter built before April 15, 1977, or first marketed before January 1, 1978, is exempt from this requirement. </div><div><br></div><div
style="background-color: transparent;"><span></span></div><div>(e) The mean power of any spurious emission from a station transmitter or external RF power amplifier transmitting on a frequency between 30-225 MHz must be at least 60 dB below the mean power of the fundamental. For a transmitter having a mean power of 25 W or less, the mean power of any spurious emission supplied to the antenna transmission line must not exceed 25 µW and must be at least 40 dB below the mean power of the fundamental emission, but need not be reduced below the power of 10 µW. A transmitter built before April 15, 1977, or first marketed before January 1, 1978, is exempt from this requirement.</div><div></div><div> </div><div>Glen, K9STH</div><div><br><br></div><div>Website: http://k9sth.com</div><div class="yahoo_quoted" style="display: block;"> <br> <br> <div style="font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif;
font-size: 12pt;"> <div style="font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-size: 12pt;"> <div dir="ltr"> <font size="2" face="Arial"> On Saturday, March 8, 2014 8:26 PM, John Klingelhoeffer <wb4lnm@aol.com> wrote:<br> </font> </div> <div class="y_msg_container"><div id="yiv9316789882"><font color="black" size="5" face="Arial, Helvetica, sans-serif">A couple of quick questions to the group regarding the HW-16 CW transceiver I am currently refurbishing.
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<div>1) I notice this has a circuit breaker in the mains primary instead of fuses. Seems like this is unusual for a Heathkit. This one is working fine, but I'm wondering if there have been any electrical safety problems with that approach over the years the HW-16 has been in the wild? (note: I've already changed to a 3-wire grounding AC mains cord and plug.) </div>
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<div>2) I'd have to believe that the transmitter met the FCC requirements for harmonic and spurious emissions at the time it was designed and manufactured, but has anyone taken measurements on an HW-16 'lately' to see if it meets current requirements? </div>
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<div>3) Has anyone come up with an AGC circuit for the HW-16 that works without adversely affecting the very good full-break-in QSK keying functionality? Running with no AGC is a real pain both operationally and on the ears. </div>
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<div>4) Has anyone come up with a more pleasing sidetone oscillator that is simple to integrate into the current circuity (phase-shift oscillator or something) rather than the somewhat raucous and raspy neon bulb relaxation oscillator? I'd sure like an internal sidetone option with a more pleasing tone. I can adjust the amplitude of the current oscillator, but the waveform is just downright lousy. </div>
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<div>Thanks and 73 WB4LNM</div>
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