I posted a note about winding an osc. coil & wave trap build on the forum. Has anyone seen this & does anybody have any ideas? I forgot to put a topic on the heading--it was blank. Would like to get a few ideas on how to procede. It's like a fork --which way does a person go when attemping to tackle a rather TOUCHY chore? And is it possible????

:I posted a note about winding an osc. coil & wave trap build on the forum. Has anyone seen this & does anybody have any ideas? I forgot to put a topic on the heading--it was blank. Would like to get a few ideas on how to procede. It's like a fork --which way does a person go when attemping to tackle a rather TOUCHY chore? And is it possible????
:
= = = = = = = = =

This may help if you are starting from scratch:
http://136.159.225.44/AlliedData2.pdf

If you are trying to replace an open winding on an existing aircore form coil, it's much easier since the wire gauge, coil diameter, and # of turns are already figured out for you. Just dewax the coil, unwind it, and rewind it with new wire, making sure that you wind the new wire in the same direction as the original. The results won't be pretty if you handwind it, but it will work fine. WIRE DIAMETER, TURN COUNT, and WINDING DIRECTION are the key things that you need to duplicate. I've successfully handwound several standard-broadcast radio oscillator coils this way.

After the coil has been installed and is working, you might want to "paint" it with molten beeswax to keep moisture (and corrosion) out.

::I posted a note about winding an osc. coil & wave trap build on the forum. Has anyone seen this & does anybody have any ideas? I forgot to put a topic on the heading--it was blank. Would like to get a few ideas on how to procede. It's like a fork --which way does a person go when attemping to tackle a rather TOUCHY chore? And is it possible????
: I stand corrected, darn!!I forgot to mention that the original osc. coil was taken OUT & replaced with a std. BC coil with a primary & a secondary. The EMERSON BL-210 had two bands, BC, & MARINE. The BC band is real close to the dial markings with the (make-shift) or replacement coil. The riders shows a tapped coil which serves both bands; the full winding for BC & the lesser winding for the MARINE. Because I have no statistics for resistance, I have to start from scratch. Could a newer coil from these newer ZENITH'S where they used a tapped osc. coil & a slug for adjusting the lower end of the dial be used? I know that the freq. would not be right but at least it's something???? Now how about winding a wave trap ----or---- using one of these newer rf chokes( little blue ones like a short erasure with little dots). Would they be just as good, after all they are a little inductor. ZENITH used them in tvs in the if section. The cap. could be DETERMINED IN TEST with a decade or a substitution box. The coil & cap. are in series to b- or chassis. I have an old ZENITH that uses a wave trap, got it from rider's ZENITH 6-D- 520. Something different but on coils. My old ZENITH 5-D-611 uses a combination speaker field coil/out-put transformerset-up. first time I've seen that set-up! The sec. for the speaker voice coil is also wound around the field coil. The absence of an output transformer saves a few dollars. Surprisingly it works OK. If anyone would like to check this setup out look under ZENITH & check out 5-D-611. Thanks for responding, I wasn't very clear in the first message. Hope whoever reads this will have a more clearer understanding so they can give a MORE ACCURATE reply.
:
:
:This may help if you are starting from scratch:
:http://136.159.225.44/AlliedData2.pdf
:
:If you are trying to replace an open winding on an existing aircore form coil, it's much easier since the wire gauge, coil diameter, and # of turns are already figured out for you. Just dewax the coil, unwind it, and rewind it with new wire, making sure that you wind the new wire in the same direction as the original. The results won't be pretty if you handwind it, but it will work fine. WIRE DIAMETER, TURN COUNT, and WINDING DIRECTION are the key things that you need to duplicate. I've successfully handwound several standard-broadcast radio oscillator coils this way.
:
:After the coil has been installed and is working, you might want to "paint" it with molten beeswax to keep moisture (and corrosion) out.
:
:
:

:: I stand corrected, darn!!I forgot to mention that the original osc. coil was taken OUT & replaced with a std. BC coil with a primary & a secondary. The EMERSON BL-210 had two bands, BC, & MARINE. The BC band is real close to the dial markings with the (make-shift) or replacement coil. The riders shows a tapped coil which serves both bands; the full winding for BC & the lesser winding for the MARINE. Because I have no statistics for resistance, I have to start from scratch. Could a newer coil from these newer ZENITH'S where they used a tapped osc. coil & a slug for adjusting the lower end of the dial be used? I know that the freq. would not be right but at least it's something???? Now how about winding a wave trap ----or---- using one of these newer rf chokes( little blue ones like a short erasure with little dots). Would they be just as good, after all they are a little inductor. ZENITH used them in tvs in the if section. The cap. could be DETERMINED IN TEST with a decade or a substitution box. The coil & cap. are in series to b- or chassis. I have an old ZENITH that uses a wave trap, got it from rider's ZENITH 6-D- 520. Something different but on coils. My old ZENITH 5-D-611 uses a combination speaker field coil/out-put transformerset-up. first time I've seen that set-up! The sec. for the speaker voice coil is also wound around the field coil. The absence of an output transformer saves a few dollars. Surprisingly it works OK. If anyone would like to check this setup out look under ZENITH & check out 5-D-611. Thanks for responding, I wasn't very clear in the first message. Hope whoever reads this will have a more clearer understanding so they can give a MORE ACCURATE reply.

= = = = = = = = =

Remove the oscillator coil and unwind about 30-40% of it. Then solder a wire to that point, creating a 3-way "tap". Rewind the coil. Solder the tap wire to the bandswitch segment that shorts the tap to ground in "Police" band mode. That should get you in the ballpark for the police band of this Emerson, which is just above the broadcast band (so the number of coil turns is less than for the BC band). This mod also should not dramatically affect the broadcast band, although you will probably have to adjust the padders to get exact dial tracking due to the presence of the tap.

Not certain, but I don't think analog TV IF frequencies were the same as AM radios. But it would be easy enough to calculate a LC combination that is needed to achieve resonance at 455 KHz, and wind a coil based on that.

::: I stand corrected, darn!!I forgot to mention that the original osc. coil was taken OUT & replaced with a std. BC coil with a primary & a secondary. The EMERSON BL-210 had two bands, BC, & MARINE. The BC band is real close to the dial markings with the (make-shift) or replacement coil. The riders shows a tapped coil which serves both bands; the full winding for BC & the lesser winding for the MARINE. Because I have no statistics for resistance, I have to start from scratch. Could a newer coil from these newer ZENITH'S where they used a tapped osc. coil & a slug for adjusting the lower end of the dial be used? I know that the freq. would not be right but at least it's something???? Now how about winding a wave trap ----or---- using one of these newer rf chokes( little blue ones like a short erasure with little dots). Would they be just as good, after all they are a little inductor. ZENITH used them in tvs in the if section. The cap. could be DETERMINED IN TEST with a decade or a substitution box. The coil & cap. are in series to b- or chassis. I have an old ZENITH that uses a wave trap, got it from rider's ZENITH 6-D- 520. Something different but on coils. My old ZENITH 5-D-611 uses a combination speaker field coil/out-put transformerset-up. first time I've seen that set-up! The sec. for the speaker voice coil is also wound around the field coil. The absence of an output transformer saves a few dollars. Surprisingly it works OK. If anyone would like to check this setup out look under ZENITH & check out 5-D-611. Thanks for responding, I wasn't very clear in the first message. Hope whoever reads this will have a more clearer understanding so they can give a MORE ACCURATE reply.
:
:
:= = = = = = = = =
:
:Remove the oscillator coil and unwind about 30-40% of it. Then solder a wire to that point, creating a 3-way "tap". Rewind the coil. Solder the tap wire to the bandswitch segment that shorts the tap to ground in "Police" band mode. That should get you in the ballpark for the police band of this Emerson, which is just above the broadcast band (so the number of coil turns is less than for the BC band). This mod also should not dramatically affect the broadcast band, although you will probably have to adjust the padders to get exact dial tracking due to the presence of the tap.
:
:Not certain, but I don't think analog TV IF frequencies were the same as AM radios. But it would be easy enough to calculate a LC combination that is needed to achieve resonance at 455 KHz, and wind a coil based on that.

As I remember, the video IF was around 40 mHz, the audio IF was 4.5 mHz, due to using the picture carrier as the sound local oscillator. Overmodulation of the picture created a buzz in the sound.
Lewis
:
:
: