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- Thread starter kopcicle
- Start date
I have never approved of huffing nitrous or any other chemicals when driving.
Driving ruins the Rush!
Heath’s intended frequencies for the carrier oscillator were 3393.6 kHz LSB, 3396.6 kHz
USB, and 3395.4 kHz for CW. With the specified filter center-frequency of 3395.0 kHz
the USB & LSB carrier positions would be 1.6 kHz each side of the filter center-
frequency. Unfortunately, the filter center-frequency may not be exactly 3395.0 kHz, so
simply placing the carrier injection points equally-spaced from 3395 kHz may not have
the intended result. In order to determine the filter center-frequency one must balance the
audio response between both sidebands, measure the USB and LSB carrier frequencies,
and finally subtract 1⁄2 the difference between the USB & LSB frequencies from the USB
carrier frequency. The result will be the I.F. filter center-frequency as it exists within
your particular rig. For example, if the audio response is exactly the same between
USB/LSB, and the measured USB carrier frequency is 3396.31 kHz while the LSB
carrier frequency measures 3393.51 kHz, then the difference is 3396.31 - 3393.51 = 2.8
kHz. One-half the difference is 2.8 ÷ 2, or 1.4 kHz. Then the USB frequency of 3396.31
kHz - 1.4 kHz = 3394.91 kHz, which in this example is the actual SSB filter center
frequency.
I like audio with a tad bit more bottom end response, so I placed my carrier points just a
little closer to the filter center frequency than the Heath spec., i.e., rather than 1.6 kHz off
center I went with 1.4 kHz. The frequency of the oscillator is lowered by placing a small
amount of capacitance in parallel with the crystal, and the frequency is raised by putting
capacitance in series with the crystal. To put a capacitor in series with the crystal simply
cut one circuit board trace just before the crystal pin as indicated, and solder the capacitor
across the opened trace (Figure 4). A 100 pf capacitor in series will move the crystal
frequency up about 100 Hz, but the same frequency change in the downward direction
would only require about 10 pf connected in parallel with the crystal.
Optimizing the Heathkit HW-101, SB100-102 Transceivers
KB2LJJ JOAO F RIBEIRO,
USB, and 3395.4 kHz for CW. With the specified filter center-frequency of 3395.0 kHz
the USB & LSB carrier positions would be 1.6 kHz each side of the filter center-
frequency. Unfortunately, the filter center-frequency may not be exactly 3395.0 kHz, so
simply placing the carrier injection points equally-spaced from 3395 kHz may not have
the intended result. In order to determine the filter center-frequency one must balance the
audio response between both sidebands, measure the USB and LSB carrier frequencies,
and finally subtract 1⁄2 the difference between the USB & LSB frequencies from the USB
carrier frequency. The result will be the I.F. filter center-frequency as it exists within
your particular rig. For example, if the audio response is exactly the same between
USB/LSB, and the measured USB carrier frequency is 3396.31 kHz while the LSB
carrier frequency measures 3393.51 kHz, then the difference is 3396.31 - 3393.51 = 2.8
kHz. One-half the difference is 2.8 ÷ 2, or 1.4 kHz. Then the USB frequency of 3396.31
kHz - 1.4 kHz = 3394.91 kHz, which in this example is the actual SSB filter center
frequency.
I like audio with a tad bit more bottom end response, so I placed my carrier points just a
little closer to the filter center frequency than the Heath spec., i.e., rather than 1.6 kHz off
center I went with 1.4 kHz. The frequency of the oscillator is lowered by placing a small
amount of capacitance in parallel with the crystal, and the frequency is raised by putting
capacitance in series with the crystal. To put a capacitor in series with the crystal simply
cut one circuit board trace just before the crystal pin as indicated, and solder the capacitor
across the opened trace (Figure 4). A 100 pf capacitor in series will move the crystal
frequency up about 100 Hz, but the same frequency change in the downward direction
would only require about 10 pf connected in parallel with the crystal.
Optimizing the Heathkit HW-101, SB100-102 Transceivers
KB2LJJ JOAO F RIBEIRO,
VERY CLEAN...Sweet...
Did you do all the updates?
http://www.pestingers.net/pdfs/heathkit-radios/hw101-mods-updates.pdf
All the Best
Gary
https://www.ebay.ca/itm/Heathkit-HW...651758?hash=item3d158e4a6e:g:zeAAAOSwAvJW9vQM
Did you do all the updates?
http://www.pestingers.net/pdfs/heathkit-radios/hw101-mods-updates.pdf
All the Best
Gary
https://www.ebay.ca/itm/Heathkit-HW...651758?hash=item3d158e4a6e:g:zeAAAOSwAvJW9vQM
- No one is chatting at the moment.