:
:

: : : : : : : : : : :Sir Brian . . . . . : : :There is one aspect to the tuning condensers position. : : :One is typically seeing the manner of injection of the signal generator output into the aligned set at 455/6 as being either thru inductive / close capacitive coupling of an adjunct "dummy" loop antenna positioned into a required proximity of the aligned sets loop antenna . . OR . . . thru loose coupling into the set via a coupling capacitor into the mixer stages RF portion. : : :Now even though the input loop /or/ antenna coil /tuning condenser combination is NOT capable of resonating WAY on down to 455, there will be a greater degree of enhancement of the injected signal with that tuned circuitry being there, if the plates are fully meshed, to be bringing that resonant circuit down around 540 Khz, as compared to them being fully unmeshed and with a much higher ~1750 Khz circuit then being present on that circuitry. : : : :In consulting the units schematic of the mixer circuitry, and your drop out problems on the high BC band, can you confirm that the Filament supply to the mixer tube is high enough to be giving reliable emission . . . particularly affecting the oscillator activity at the high end of the band on a battery powered set . . . . (Great shades of a 1L6 . . as in a Zenith Transoceanic . . but that IS occurring at a much higher frequency !) : : :That would be a full 2VDC across the filament and not 1.5 VDC. : : :Check some resistors: : : :Check that 51,000 ohm grid resistor, to see if it is of that value and not drifted upwards to 100K+. : : :And then there is that R2, 10 K that supplies B+ to the oscillator circuit. Beside it, sits that .01 capacitor which you would be wanting to be having . . . ZEEEERO . . . DC voltage leaking thru it. : : :Now I would certainly, be fully expecting that C3 osc grid coupling capacitor to be a quality silver mica . . . typically lasts forever, is stable, and the most troublefree type of capacitor, in low capacitance categories. : : :BUT, do place your ohmmeter across it and see if it then passes an open circuit category test, (no leakage). : : :Since it does have DC isolative capacitors tied onto its right side circuitry. : : : : : :It would also be nice to have the DC voltage measurements of the plate of the mixer along with the second grid up . . . which REALLY thinks it's a plate, in its local oscillator function. : : : : :On Page Mixer Schematic Referencing: : : : : : : : : :And finally . . . did you actually find L2 oscillator coil to be having a tuning slug adjustment within it ? : : :Not being shown as such on the schematic . . .unless, years later, a person put in a new "universal" oscillator coil. :Does its peripheral wiring, and soldering tend to suggest that ? : : :I was sort of expecting that old of a unit to be using a big 3/4 to 1 inch open coil form, but, if being slug tuned that would then tend to reduce the coil form sizing down to being an ~ 3/8 to 1/2 inch coil form with its inner slug. : : :If so, come back and I will fill you in on the tuning procedure for THAT particular situation. : : : : : : : :73's de Edd : : : :

:
:
:
:
:
:
:
:
::Hi Vin
::
:: If really doesn't matter when aligning IF stages with a signal generator. IF stages are after the tuner.
::
::Norm
::
::
::
:::I have just started reading and learning about alignment. I have one question that is not answered in the reading so far. At what frequency is the receiver set to when aligning the IF stage.
:::Vin
:::
::
: