Amy ideas? Thanks, Mark
You might make these steps for a tuner tracking analysis . . . . . assuming that the units chassis IS mounted within the cabinet as was mentioned in the alignment info..
With them considering the proximity of metal near the loop antenna being a pre considered skewing of the effective loop inductance.
Then . . . .you didn’t mention if any station could be heard below 700, if one can be picked up, then use it as your reference and concentrate on your two tuning condenser trimmers, C6 for the RF aspect and C2 for your Oscillator adjustments and.
Initially bring your hand up and press against the loop proper’s wiring and see if the signal level of that received station comes up
.OR else it goes down in level.
Then . . .considering that the tuning caps trimmer screws are std slotted screws. . . take a fine Sharpie marker and make a reference tick mark that is on the trimmers top leaf and referencing to the trimmers screw slot, doing the same on both RF C6 and Osc C2 trimmers.
Afterwards in the testing, you shouldn’t have to swing the RF trimmer adjustment, any more than ¼ turn in both directions to see if that reference station is coming in stronger. With you then leaving its final setting back to the referencing mark .
.NOW. . . the next aspect is a bit touchier to perceive. You will be doing the same ¼ turn in either direction of the Oscillators C2 trimmer cap this time.
Of course, in the moving of the C2 trimmer that station will have been drifted away from. . . .S o o o o. . . you have to micro-compensate by hand manipulating the tuning condenser shaft to get back onto station. Then you make another micro movement of the trimmer and
retune onto the station. The procedure is repetitive until you reach that + and - ¼ turn of C2.
This procedure is the easiest to do if you will grab the pulley on the tuning condenser and use it as a giant knob, thus avoiding the interim gearing down procedure via the tuning knob shaft and intra dial stringing. When you try this, after a bit, you will be inter manipulating the two adjustments flawlessly, and .THEN . . . your mind can kick in to evaluate if the signal is getting stronger or weaker as you go that full ¼ turn in and out of C2.
Try those 3 initial evaluative procedures to see what compensating procedures for low band tracking are needed. . . .IF. . . you find that the station is coming in appreciably better with the RF or the Osc trimmers being set off from your initial alignments reference tick mark references.
73's de Edd
If I set my signal generator to 550KHz (checked against another radio w/digital tuning), then using a loop near the Philco's loop antenna, tune Mr. Philco until I get a signal, the 550 KHz signal is coming in at 625 KHz on the dial. Turning the osc. trimmer counter-clockwise I can get it to come in a little lower, but still above 600 (even with screw backed all the way out). So it would seem that the tracking is way off at the low end of the scale and gets better going up.
Mark
:
:
:
:
:
:
:
:
:
:You might make these steps for a tuner tracking analysis . . . . . assuming that the units chassis IS mounted within the cabinet as was mentioned in the alignment info..
:With them considering the proximity of metal near the loop antenna being a pre considered skewing of the effective loop inductance.
:
:
:
:Then . . . .you didn’t mention if any station could be heard below 700, if one can be picked up, then use it as your reference and concentrate on your two tuning condenser trimmers, C6 for the RF aspect and C2 for your Oscillator adjustments and.
:Initially bring your hand up and press against the loop proper’s wiring and see if the signal level of that received station comes up
:.OR else it goes down in level.
:
:Then . . .considering that the tuning caps trimmer screws are std slotted screws. . . take a fine Sharpie marker and make a reference tick mark that is on the trimmers top leaf and referencing to the trimmers screw slot, doing the same on both RF C6 and Osc C2 trimmers.
:Afterwards in the testing, you shouldn’t have to swing the RF trimmer adjustment, any more than ¼ turn in both directions to see if that reference station is coming in stronger. With you then leaving its final setting back to the referencing mark .
:
:
:.NOW. . . the next aspect is a bit touchier to perceive. You will be doing the same ¼ turn in either direction of the Oscillators C2 trimmer cap this time.
:
:Of course, in the moving of the C2 trimmer that station will have been drifted away from. . . .S o o o o. . . you have to micro-compensate by hand manipulating the tuning condenser shaft to get back onto station. Then you make another micro movement of the trimmer and
:retune onto the station. The procedure is repetitive until you reach that + and - ¼ turn of C2.
:
:This procedure is the easiest to do if you will grab the pulley on the tuning condenser and use it as a giant knob, thus avoiding the interim gearing down procedure via the tuning knob shaft and intra dial stringing. When you try this, after a bit, you will be inter manipulating the two adjustments flawlessly, and .THEN . . . your mind can kick in to evaluate if the signal is getting stronger or weaker as you go that full ¼ turn in and out of C2.
:
:
:
:Try those 3 initial evaluative procedures to see what compensating procedures for low band tracking are needed. . . .IF. . . you find that the station is coming in appreciably better with the RF or the Osc trimmers being set off from your initial alignments reference tick mark references.
:
:
:
:73's de Edd
:
:
:
:
:
:
:
:Mr. Edd,
:
:If I set my signal generator to 550KHz (checked against another radio w/digital tuning), then using a loop near the Philco's loop antenna, tune Mr. Philco until I get a signal, the 550 KHz signal is coming in at 625 KHz on the dial. Turning the osc. trimmer counter-clockwise I can get it to come in a little lower, but still above 600 (even with screw backed all the way out). So it would seem that the tracking is way off at the low end of the scale and gets better going up.
:
:Mark
:
:
::
::
::
::
::
::
::
::
::
::You might make these steps for a tuner tracking analysis . . . . . assuming that the units chassis IS mounted within the cabinet as was mentioned in the alignment info..
::With them considering the proximity of metal near the loop antenna being a pre considered skewing of the effective loop inductance.
::
::
::
::Then . . . .you didn’t mention if any station could be heard below 700, if one can be picked up, then use it as your reference and concentrate on your two tuning condenser trimmers, C6 for the RF aspect and C2 for your Oscillator adjustments and.
::Initially bring your hand up and press against the loop proper’s wiring and see if the signal level of that received station comes up
::.OR else it goes down in level.
::
::Then . . .considering that the tuning caps trimmer screws are std slotted screws. . . take a fine Sharpie marker and make a reference tick mark that is on the trimmers top leaf and referencing to the trimmers screw slot, doing the same on both RF C6 and Osc C2 trimmers.
::Afterwards in the testing, you shouldn’t have to swing the RF trimmer adjustment, any more than ¼ turn in both directions to see if that reference station is coming in stronger. With you then leaving its final setting back to the referencing mark .
::
::
::.NOW. . . the next aspect is a bit touchier to perceive. You will be doing the same ¼ turn in either direction of the Oscillators C2 trimmer cap this time.
::
::Of course, in the moving of the C2 trimmer that station will have been drifted away from. . . .S o o o o. . . you have to micro-compensate by hand manipulating the tuning condenser shaft to get back onto station. Then you make another micro movement of the trimmer and
::retune onto the station. The procedure is repetitive until you reach that + and - ¼ turn of C2.
::
::This procedure is the easiest to do if you will grab the pulley on the tuning condenser and use it as a giant knob, thus avoiding the interim gearing down procedure via the tuning knob shaft and intra dial stringing. When you try this, after a bit, you will be inter manipulating the two adjustments flawlessly, and .THEN . . . your mind can kick in to evaluate if the signal is getting stronger or weaker as you go that full ¼ turn in and out of C2.
::
::
::
::Try those 3 initial evaluative procedures to see what compensating procedures for low band tracking are needed. . . .IF. . . you find that the station is coming in appreciably better with the RF or the Osc trimmers being set off from your initial alignments reference tick mark references.
::
::
::
::73's de Edd
::
::
::
::
::
::
::
Thanks, Mark
:
::Mr. Edd,
::
::If I set my signal generator to 550KHz (checked against another radio w/digital tuning), then using a loop near the Philco's loop antenna, tune Mr. Philco until I get a signal, the 550 KHz signal is coming in at 625 KHz on the dial. Turning the osc. trimmer counter-clockwise I can get it to come in a little lower, but still above 600 (even with screw backed all the way out). So it would seem that the tracking is way off at the low end of the scale and gets better going up.
::
::Mark
::
::
:::
:::
:::
:::
:::
:::
:::
:::
:::
:::You might make these steps for a tuner tracking analysis . . . . . assuming that the units chassis IS mounted within the cabinet as was mentioned in the alignment info..
:::With them considering the proximity of metal near the loop antenna being a pre considered skewing of the effective loop inductance.
:::
:::
:::
:::Then . . . .you didn’t mention if any station could be heard below 700, if one can be picked up, then use it as your reference and concentrate on your two tuning condenser trimmers, C6 for the RF aspect and C2 for your Oscillator adjustments and.
:::Initially bring your hand up and press against the loop proper’s wiring and see if the signal level of that received station comes up
:::.OR else it goes down in level.
:::
:::Then . . .considering that the tuning caps trimmer screws are std slotted screws. . . take a fine Sharpie marker and make a reference tick mark that is on the trimmers top leaf and referencing to the trimmers screw slot, doing the same on both RF C6 and Osc C2 trimmers.
:::Afterwards in the testing, you shouldn’t have to swing the RF trimmer adjustment, any more than ¼ turn in both directions to see if that reference station is coming in stronger. With you then leaving its final setting back to the referencing mark .
:::
:::
:::.NOW. . . the next aspect is a bit touchier to perceive. You will be doing the same ¼ turn in either direction of the Oscillators C2 trimmer cap this time.
:::
:::Of course, in the moving of the C2 trimmer that station will have been drifted away from. . . .S o o o o. . . you have to micro-compensate by hand manipulating the tuning condenser shaft to get back onto station. Then you make another micro movement of the trimmer and
:::retune onto the station. The procedure is repetitive until you reach that + and - ¼ turn of C2.
:::
:::This procedure is the easiest to do if you will grab the pulley on the tuning condenser and use it as a giant knob, thus avoiding the interim gearing down procedure via the tuning knob shaft and intra dial stringing. When you try this, after a bit, you will be inter manipulating the two adjustments flawlessly, and .THEN . . . your mind can kick in to evaluate if the signal is getting stronger or weaker as you go that full ¼ turn in and out of C2.
:::
:::
:::
:::Try those 3 initial evaluative procedures to see what compensating procedures for low band tracking are needed. . . .IF. . . you find that the station is coming in appreciably better with the RF or the Osc trimmers being set off from your initial alignments reference tick mark references.
:::
:::
:::
:::73's de Edd
:::
:::
:::
:::
:::
:::
:::
:So today I tried a NOS 7A8 converter tube, made no difference. I realigned everything with the chassis mounted in the cabinet. The lowest station i can pick up is at 680KC, below that it's just static until the tuner cap is almost completely meshed, then I get a very loud hum. I have replaced all wax and electrolytic caps (installed one backwards first time and blew the rectifier tube, this has the voltage doubler supply with the 2 caps hooked up plus to minus which i didn't notice) I am at a loss as to what to do next. any ideas?
:
:Thanks, Mark
:
:
::
:::Mr. Edd,
:::
:::If I set my signal generator to 550KHz (checked against another radio w/digital tuning), then using a loop near the Philco's loop antenna, tune Mr. Philco until I get a signal, the 550 KHz signal is coming in at 625 KHz on the dial. Turning the osc. trimmer counter-clockwise I can get it to come in a little lower, but still above 600 (even with screw backed all the way out). So it would seem that the tracking is way off at the low end of the scale and gets better going up.
:::
:::Mark
:::
:::
::::
::::
::::
::::
::::
::::
::::
::::
::::
::::You might make these steps for a tuner tracking analysis . . . . . assuming that the units chassis IS mounted within the cabinet as was mentioned in the alignment info..
::::With them considering the proximity of metal near the loop antenna being a pre considered skewing of the effective loop inductance.
::::
::::
::::
::::Then . . . .you didn’t mention if any station could be heard below 700, if one can be picked up, then use it as your reference and concentrate on your two tuning condenser trimmers, C6 for the RF aspect and C2 for your Oscillator adjustments and.
::::Initially bring your hand up and press against the loop proper’s wiring and see if the signal level of that received station comes up
::::.OR else it goes down in level.
::::
::::Then . . .considering that the tuning caps trimmer screws are std slotted screws. . . take a fine Sharpie marker and make a reference tick mark that is on the trimmers top leaf and referencing to the trimmers screw slot, doing the same on both RF C6 and Osc C2 trimmers.
::::Afterwards in the testing, you shouldn’t have to swing the RF trimmer adjustment, any more than ¼ turn in both directions to see if that reference station is coming in stronger. With you then leaving its final setting back to the referencing mark .
::::
::::
::::.NOW. . . the next aspect is a bit touchier to perceive. You will be doing the same ¼ turn in either direction of the Oscillators C2 trimmer cap this time.
::::
::::Of course, in the moving of the C2 trimmer that station will have been drifted away from. . . .S o o o o. . . you have to micro-compensate by hand manipulating the tuning condenser shaft to get back onto station. Then you make another micro movement of the trimmer and
::::retune onto the station. The procedure is repetitive until you reach that + and - ¼ turn of C2.
::::
::::This procedure is the easiest to do if you will grab the pulley on the tuning condenser and use it as a giant knob, thus avoiding the interim gearing down procedure via the tuning knob shaft and intra dial stringing. When you try this, after a bit, you will be inter manipulating the two adjustments flawlessly, and .THEN . . . your mind can kick in to evaluate if the signal is getting stronger or weaker as you go that full ¼ turn in and out of C2.
::::
::::
::::
::::Try those 3 initial evaluative procedures to see what compensating procedures for low band tracking are needed. . . .IF. . . you find that the station is coming in appreciably better with the RF or the Osc trimmers being set off from your initial alignments reference tick mark references.
::::
::::
::::
::::73's de Edd
::::
::::
::::
::::
::::
::::
::::
Then I was looking at a book I have, Basic Radio Repair by Marvin Tepper, 1965. In the section on IF alignment, it suggests fully opening the tuning cap, with a piece of solder across the oscillator plates to short them & disable the oscillator. Which I did. Then connected generator to grid of converter tube & aligned (for 3rd time) the IF cans. Interestingly, the settings for max output were way off from the previous alignments.
And now, all tuning problems are gone! get all the local stations below 680, and everything comes in where it should!
So this is really weird because I was aligning it exactly as specified in the official Philco service info. My signal generator is a Heathkit that I built in high school waaaaaaay back in 1976. (I check the freq setting with a radio that has digital tuning and a long wave band that will tune 455 KC.) Never had this problem before on many (20+) old radios I've aligned.
Mark
:when your cap is meshing, are any of the plates from each section bent and touching the others?
:
::So today I tried a NOS 7A8 converter tube, made no difference. I realigned everything with the chassis mounted in the cabinet. The lowest station i can pick up is at 680KC, below that it's just static until the tuner cap is almost completely meshed, then I get a very loud hum. I have replaced all wax and electrolytic caps (installed one backwards first time and blew the rectifier tube, this has the voltage doubler supply with the 2 caps hooked up plus to minus which i didn't notice) I am at a loss as to what to do next. any ideas?
::
::Thanks, Mark
::
::
:::
::::Mr. Edd,
::::
::::If I set my signal generator to 550KHz (checked against another radio w/digital tuning), then using a loop near the Philco's loop antenna, tune Mr. Philco until I get a signal, the 550 KHz signal is coming in at 625 KHz on the dial. Turning the osc. trimmer counter-clockwise I can get it to come in a little lower, but still above 600 (even with screw backed all the way out). So it would seem that the tracking is way off at the low end of the scale and gets better going up.
::::
::::Mark
::::
::::
:::::
:::::
:::::
:::::
:::::
:::::
:::::
:::::
:::::
:::::You might make these steps for a tuner tracking analysis . . . . . assuming that the units chassis IS mounted within the cabinet as was mentioned in the alignment info..
:::::With them considering the proximity of metal near the loop antenna being a pre considered skewing of the effective loop inductance.
:::::
:::::
:::::
:::::Then . . . .you didn’t mention if any station could be heard below 700, if one can be picked up, then use it as your reference and concentrate on your two tuning condenser trimmers, C6 for the RF aspect and C2 for your Oscillator adjustments and.
:::::Initially bring your hand up and press against the loop proper’s wiring and see if the signal level of that received station comes up
:::::.OR else it goes down in level.
:::::
:::::Then . . .considering that the tuning caps trimmer screws are std slotted screws. . . take a fine Sharpie marker and make a reference tick mark that is on the trimmers top leaf and referencing to the trimmers screw slot, doing the same on both RF C6 and Osc C2 trimmers.
:::::Afterwards in the testing, you shouldn’t have to swing the RF trimmer adjustment, any more than ¼ turn in both directions to see if that reference station is coming in stronger. With you then leaving its final setting back to the referencing mark .
:::::
:::::
:::::.NOW. . . the next aspect is a bit touchier to perceive. You will be doing the same ¼ turn in either direction of the Oscillators C2 trimmer cap this time.
:::::
:::::Of course, in the moving of the C2 trimmer that station will have been drifted away from. . . .S o o o o. . . you have to micro-compensate by hand manipulating the tuning condenser shaft to get back onto station. Then you make another micro movement of the trimmer and
:::::retune onto the station. The procedure is repetitive until you reach that + and - ¼ turn of C2.
:::::
:::::This procedure is the easiest to do if you will grab the pulley on the tuning condenser and use it as a giant knob, thus avoiding the interim gearing down procedure via the tuning knob shaft and intra dial stringing. When you try this, after a bit, you will be inter manipulating the two adjustments flawlessly, and .THEN . . . your mind can kick in to evaluate if the signal is getting stronger or weaker as you go that full ¼ turn in and out of C2.
:::::
:::::
:::::
:::::Try those 3 initial evaluative procedures to see what compensating procedures for low band tracking are needed. . . .IF. . . you find that the station is coming in appreciably better with the RF or the Osc trimmers being set off from your initial alignments reference tick mark references.
:::::
:::::
:::::
:::::73's de Edd
:::::
:::::
:::::
:::::
:::::
:::::
:::::