I have noticed on many radios with pre-sets how much
better reception is when using the pre-sets. This is due to
a much stronger local osc signal. My question is, why
is the osc is so much stronger? All pre set osc I've
seen are tuned inductively, as opposed to capacitively
in manual mode. Is the overall Q of the osc tank
better? Just wondering what others have found in this area. Ken

Hi Ken

This has to do with alignment. Pre-sets have two adjustments for each push button. One for oscillator and the other antenna. Oscillator selects the station and antenna peaks it up.

With a tuner you have trimmer caps for the high end of the band. For low end a padder. The rest depends on alignment as you can't peak up the antenna tuner section for each station. If the IF frequency isn't set right stations across the dial won't all be peaked.

Norm

:I have noticed on many radios with pre-sets how much
:better reception is when using the pre-sets. This is due to
:a much stronger local osc signal. My question is, why
:is the osc is so much stronger? All pre set osc I've
:seen are tuned inductively, as opposed to capacitively
:in manual mode. Is the overall Q of the osc tank
:better? Just wondering what others have found in this area. Ken

:Hi Ken
:
: This has to do with alignment. Pre-sets have two adjustments for each push button. One for oscillator and the other antenna. Oscillator selects the station and antenna peaks it up.
:
: With a tuner you have trimmer caps for the high end of the band. For low end a padder. The rest depends on alignment as you can't peak up the antenna tuner section for each station. If the IF frequency isn't set right stations across the dial won't all be peaked.
:
:Norm
:
::I have noticed on many radios with pre-sets how much
::better reception is when using the pre-sets. This is due to
::a much stronger local osc signal. My question is, why
::is the osc is so much stronger? All pre set osc I've
::seen are tuned inductively, as opposed to capacitively
::in manual mode. Is the overall Q of the osc tank
::better? Just wondering what others have found in this area. Ken

::Hi Ken
::
:: This has to do with alignment. Pre-sets have two adjustments for each push button. One for oscillator and the other antenna. Oscillator selects the station and antenna peaks it up.
::
:: With a tuner you have trimmer caps for the high end of the band. For low end a padder. The rest depends on alignment as you can't peak up the antenna tuner section for each station. If the IF frequency isn't set right stations across the dial won't all be peaked.
::
::Norm
::

Not exactly sure how to use this forum??. I understand
the match between the rf and lo tuning, but why is the
osc so much stronget when on pre set? On a local station,
when in auto, the osc grid is -1v, when in preset, it
reads -5v. Big difference, and makes a big difference
in reception. Ken
:::I have noticed on many radios with pre-sets how much
:::better reception is when using the pre-sets. This is due to
:::a much stronger local osc signal. My question is, why
:::is the osc is so much stronger? All pre set osc I've
:::seen are tuned inductively, as opposed to capacitively
:::in manual mode. Is the overall Q of the osc tank
:::better? Just wondering what others have found in this area. Ken

:Hi Ken
:
: This has to do with alignment. Pre-sets have two adjustments for each push button. One for oscillator and the other antenna. Oscillator selects the station and antenna peaks it up.
:
: With a tuner you have trimmer caps for the high end of the band. For low end a padder. The rest depends on alignment as you can't peak up the antenna tuner section for each station. If the IF frequency isn't set right stations across the dial won't all be peaked.
:
:Norm

Norm, I understand the match needed between the rf
and lo, but why is the lo stronger when in pre set?
On a local station, when in manual, the osc grid reads
-1v. When in pre set, it reads -5v, same station.
::I have noticed on many radios with pre-sets how much
::better reception is when using the pre-sets. This is due to
::a much stronger local osc signal. My question is, why
::is the osc is so much stronger? All pre set osc I've
::seen are tuned inductively, as opposed to capacitively
::in manual mode. Is the overall Q of the osc tank
::better? Just wondering what others have found in this area. Ken