Hello All...

Am looking for the following:

Knobs for a Zenith C724L.

Pilot lamp for a JVC Nivico, model 88U. It is a 20V neon bulb with a screw base. Was told it is a NE 51, but haven't been able to locate any with the screw base. (This is a plastic, AM/FM tube radio, probably from the early 50's.)

Thanks Much,

Chas

Sorry, I don't have any of the stuff you are seeking, but only a bit of information. You won't find any 20 volt neon bulbs. Neon lamps require at least 60 or 70 volts to "kick over" and light up.

Rich

:Hello All...
:
:Am looking for the following:
:
:Knobs for a Zenith C724L.
:
:Pilot lamp for a JVC Nivico, model 88U. It is a 20V neon bulb with a screw base. Was told it is a NE 51, but haven't been able to locate any with the screw base. (This is a plastic, AM/FM tube radio, probably from the early 50's.)
:
:Thanks Much,
:
:Chas

Chas: The NE51 is a neon glow lamp, 105-125v, single contact bayonet base. You might want to do some further research.

Knobs for a Zenith C724L......Ah, yes just got in a fresh shipment the other day, but I'm sure that they would be of no interest to you, with them all being left handed models.

Also concur on the neon lamp, as they require ~65-70 volts for their ionization threshold.

However I probably can help you in your further research/troubleshooting techniques refinement.
I am assuming that you have no schematic , as even I can't find any thing on it....in either Sams or on the Web for free!
I am assuming the lamp to be a very small lamp with its base being at least half the size or less as a common # 50 screw terminal lamp utilizes.The possible reason of the assumption of it being a neon might have been the lamps top glass profile having a "tit" on it like the common NE-2 lamp does....but with its having wire leads. Unless you have seen it working...who is to say that it even lit up orange? Also I might assume it to be of a dial light nature in its use instead of an FM tuner indicator lamp.
With those "assumptions" out of the way , lets get the two leads that feed the lamp connected to some test jumper leads and remote then away a bit so that they can then be connected to a common low wattage 120 VAC incandescant lamp. In that manner, you will be presenting only minumal loading to the feeder supply.
Power up the set and take a reading across the lamp to see if the feed is AC or DC power and you will then be able to see the maximum voltage present ...specifically at that lamps loading factor. Then after you have read/logged the voltage present , you can then open the series circuit and place the milliameter function of your metering medium in series with the load to ascertain the actual current comsumption occuring. With those figures in hand, you can then compute the wattage being sent down the supply line and ascertain the voltage and current rating of a lamp that would meet those same parameters.

Personally, I am expecting the original lamp to be a based variant of what was sometimes referred to as a grain of wheat lamp....but in a somewhat healthier size of envelope, along with the "tit" on the envelopes glass end, as well as a very sub miniature sized screw base. If you happen to actually HAVE the original lamp in hand you could readily ascertain its genre by visual inspection. The neon lamp merely has a pair of separate electrodes that stick up inside the envelope, whereas , you will see a tandem filament support infrastructure with the interconnecting filament....or remnants therof....within the envelope coming up from the base if the unit was an incandescant design of lamp.
Any lamp light colorization typically would been from a tinting of the glass envelope.
On the test above, I was thinking of a low power 120VAC lamp in the order of a 6S6 , very old sytle christmas tree lamp/bulb or even one of the small lamps temporarily lifted from Mamacita's sewing machine lamp or microwave internal light or even some hi intensity desk lamps that are not using a 6 or 12 Volt hi current lamp, and instead using a miniature 120VAC lamp.

Come back when you find the voltage and current spec's computed on the lamp....if you don't have a cornucopia of lamp specifications. One could then crack away the old glass envelope and replace it with a suitable leaded lamp and re-install it into the base and ring epoxy its envelope in into the base to have a replica screw in lamp, as that original lamp may just be an impossibility to find.

73's de Edd

:Knobs for a Zenith C724L......Ah, yes just got in a fresh shipment the other day, but I'm sure that they would be of no interest to you, with them all being left handed models.
:
:Also concur on the neon lamp, as they require ~65-70 volts for their ionization threshold.
:
:However I probably can help you in your further research/troubleshooting techniques refinement.
:I am assuming that you have no schematic , as even I can't find any thing on it....in either Sams or on the Web for free!
:I am assuming the lamp to be a very small lamp with its base being at least half the size or less as a common # 50 screw terminal lamp utilizes.The possible reason of the assumption of it being a neon might have been the lamps top glass profile having a "tit" on it like the common NE-2 lamp does....but with its having wire leads. Unless you have seen it working...who is to say that it even lit up orange? Also I might assume it to be of a dial light nature in its use instead of an FM tuner indicator lamp.
:With those "assumptions" out of the way , lets get the two leads that feed the lamp connected to some test jumper leads and remote then away a bit so that they can then be connected to a common low wattage 120 VAC incandescant lamp. In that manner, you will be presenting only minumal loading to the feeder supply.
:Power up the set and take a reading across the lamp to see if the feed is AC or DC power and you will then be able to see the maximum voltage present ...specifically at that lamps loading factor. Then after you have read/logged the voltage present , you can then open the series circuit and place the milliameter function of your metering medium in series with the load to ascertain the actual current comsumption occuring. With those figures in hand, you can then compute the wattage being sent down the supply line and ascertain the voltage and current rating of a lamp that would meet those same parameters.
:
:Personally, I am expecting the original lamp to be a based variant of what was sometimes referred to as a grain of wheat lamp....but in a somewhat healthier size of envelope, along with the "tit" on the envelopes glass end, as well as a very sub miniature sized screw base. If you happen to actually HAVE the original lamp in hand you could readily ascertain its genre by visual inspection. The neon lamp merely has a pair of separate electrodes that stick up inside the envelope, whereas , you will see a tandem filament support infrastructure with the interconnecting filament....or remnants therof....within the envelope coming up from the base if the unit was an incandescant design of lamp.
:Any lamp light colorization typically would been from a tinting of the glass envelope.
:On the test above, I was thinking of a low power 120VAC lamp in the order of a 6S6 , very old sytle christmas tree lamp/bulb or even one of the small lamps temporarily lifted from Mamacita's sewing machine lamp or microwave internal light or even some hi intensity desk lamps that are not using a 6 or 12 Volt hi current lamp, and instead using a miniature 120VAC lamp.
:
:Come back when you find the voltage and current spec's computed on the lamp....if you don't have a cornucopia of lamp specifications. One could then crack away the old glass envelope and replace it with a suitable leaded lamp and re-install it into the base and ring epoxy its envelope in into the base to have a replica screw in lamp, as that original lamp may just be an impossibility to find.
:
:73's de Edd
:
Guys,

I think he left the one (1) off when he keyed in his post. He probably needs something like an NE45 or NE52 for replacement. Or possibly if a series resistor is used between the lamp and supply voltage could be defective.

Radiodoc

Zenith C724L is covered in SAMS 484-18. I'll look later right now I got fuzz in one eye and it's time to get a bite.

Bill VA

::Knobs for a Zenith C724L......Ah, yes just got in a fresh shipment the other day, but I'm sure that they would be of no interest to you, with them all being left handed models.
::
::Also concur on the neon lamp, as they require ~65-70 volts for their ionization threshold.
::
::However I probably can help you in your further research/troubleshooting techniques refinement.
::I am assuming that you have no schematic , as even I can't find any thing on it....in either Sams or on the Web for free!
::I am assuming the lamp to be a very small lamp with its base being at least half the size or less as a common # 50 screw terminal lamp utilizes.The possible reason of the assumption of it being a neon might have been the lamps top glass profile having a "tit" on it like the common NE-2 lamp does....but with its having wire leads. Unless you have seen it working...who is to say that it even lit up orange? Also I might assume it to be of a dial light nature in its use instead of an FM tuner indicator lamp.
::With those "assumptions" out of the way , lets get the two leads that feed the lamp connected to some test jumper leads and remote then away a bit so that they can then be connected to a common low wattage 120 VAC incandescant lamp. In that manner, you will be presenting only minumal loading to the feeder supply.
::Power up the set and take a reading across the lamp to see if the feed is AC or DC power and you will then be able to see the maximum voltage present ...specifically at that lamps loading factor. Then after you have read/logged the voltage present , you can then open the series circuit and place the milliameter function of your metering medium in series with the load to ascertain the actual current comsumption occuring. With those figures in hand, you can then compute the wattage being sent down the supply line and ascertain the voltage and current rating of a lamp that would meet those same parameters.
::
::Personally, I am expecting the original lamp to be a based variant of what was sometimes referred to as a grain of wheat lamp....but in a somewhat healthier size of envelope, along with the "tit" on the envelopes glass end, as well as a very sub miniature sized screw base. If you happen to actually HAVE the original lamp in hand you could readily ascertain its genre by visual inspection. The neon lamp merely has a pair of separate electrodes that stick up inside the envelope, whereas , you will see a tandem filament support infrastructure with the interconnecting filament....or remnants therof....within the envelope coming up from the base if the unit was an incandescant design of lamp.
::Any lamp light colorization typically would been from a tinting of the glass envelope.
::On the test above, I was thinking of a low power 120VAC lamp in the order of a 6S6 , very old sytle christmas tree lamp/bulb or even one of the small lamps temporarily lifted from Mamacita's sewing machine lamp or microwave internal light or even some hi intensity desk lamps that are not using a 6 or 12 Volt hi current lamp, and instead using a miniature 120VAC lamp.
::
::Come back when you find the voltage and current spec's computed on the lamp....if you don't have a cornucopia of lamp specifications. One could then crack away the old glass envelope and replace it with a suitable leaded lamp and re-install it into the base and ring epoxy its envelope in into the base to have a replica screw in lamp, as that original lamp may just be an impossibility to find.
::
::73's de Edd
::
:Guys,
:
:I think he left the one (1) off when he keyed in his post. He probably needs something like an NE45 or NE52 for replacement. Or possibly if a series resistor is used between the lamp and supply voltage could be defective.
:
:Radiodoc
:

Thanks All for the replies:

Unfortunately I cannot use the left-handed knobs for the Zenith. I checked the Brittanica Resource Directory on Zenith plastic case sets and it specifies that the C724L was sold to right-handed consumers only, due to the color of the cabinet. It further specifies that left-handed knobs may only be substituted if the cabinet is painted white and then has Rose designs applied. I do not intend to do that. As I have already invested heavily on the purchase of this radio (99 cents) I have no desire to do anything to decrease its value.

As for the lamp for the JVC Nivico... I have the old bulb. The base is clearly stamped 20V, which is followed by three asian characters in an oval. The bulb measures 1 1/8" from tip of base to top of glass bulb, and the base is 3/8" in diameter. Inside the glass bulb there is a glass post with two wires in it. The wires come out of the top of the post and each wire is attached to a square "plate." The plates do not touch, and are not connected in any way. The inside of the glass bulb is pretty well smoked.

The bulb mounts behind a red lens on the front of the radio, I would assume to light up when the radio is turned on. This is uneducated speculation on my part. Perhaps the illumination of this lamp indicates the approach of Godzilla, and if I plugged the radio in, turned it on, and dropped it in water it would destroy all the oxygen in the water thus eliminating any threat from large ocean creatures. As such, it is a valuable device to keep on hand, and my need for a good bulb should be painfully obvious.

Was told it was a neon bulb by the clerk at a local lighting supply store. We went through all his catalogs and could not find a replacement. Have looked at several bulb sources on line with no success. Have called JVC and the rep there couldn't find any reference to a Model 88U radio.

Seems like a quest into the unknown.

Thanks Again-

Chas

Chas,

All kidding aside, I checked my box of loose lamps and I have found a neon bulb like the one you described. I tested the bulb and it works. Send me an email with your address and I will send it to you. Be sure to list in the subject line NEON BULB so the email will not be deleted.

Radiodoc

:Thanks All for the replies:
:
:Unfortunately I cannot use the left-handed knobs for the Zenith. I checked the Brittanica Resource Directory on Zenith plastic case sets and it specifies that the C724L was sold to right-handed consumers only, due to the color of the cabinet. It further specifies that left-handed knobs may only be substituted if the cabinet is painted white and then has Rose designs applied. I do not intend to do that. As I have already invested heavily on the purchase of this radio (99 cents) I have no desire to do anything to decrease its value.
:
:As for the lamp for the JVC Nivico... I have the old bulb. The base is clearly stamped 20V, which is followed by three asian characters in an oval. The bulb measures 1 1/8" from tip of base to top of glass bulb, and the base is 3/8" in diameter. Inside the glass bulb there is a glass post with two wires in it. The wires come out of the top of the post and each wire is attached to a square "plate." The plates do not touch, and are not connected in any way. The inside of the glass bulb is pretty well smoked.
:
:The bulb mounts behind a red lens on the front of the radio, I would assume to light up when the radio is turned on. This is uneducated speculation on my part. Perhaps the illumination of this lamp indicates the approach of Godzilla, and if I plugged the radio in, turned it on, and dropped it in water it would destroy all the oxygen in the water thus eliminating any threat from large ocean creatures. As such, it is a valuable device to keep on hand, and my need for a good bulb should be painfully obvious.
:
:Was told it was a neon bulb by the clerk at a local lighting supply store. We went through all his catalogs and could not find a replacement. Have looked at several bulb sources on line with no success. Have called JVC and the rep there couldn't find any reference to a Model 88U radio.
:
:Seems like a quest into the unknown.
:
:Thanks Again-
:
:Chas

From all of your description as well as the dimensions, it certainly sounds like a neon, even with the enhancement of the electrodes surface area with the addition of a couple of square plates. The already specified American lamps do have a somewhat larger bulb profile than the dimensions that you have given. The darkening of the internals is also coincident with a neon lamp with some degree of use, however it is also apparent on a well used incandescent lamp. BUT this is assuming that you saw no evidence of the skimpier support structure for a filament ……but that is almost assuredly not the case with your reference to the HEAVIER electrodes with supplemental “plates”.
One thing that you did not mention is if the end of the bulb profile is rounded off as is common, or is pulled to a small”tit’.
Le Radio-Docteur seemed to have been right on it in the thought of the ?20 numerical designator, but that omission just might have been on the part of the bulb manufacturer and his marking , as neon or argon just doesn’t ionize and strikeover at a 20 V level.
You still might take both an AC and DC voltage reading on the units wiring terminals when powered up to actually see what is present and being supplied to the lamp circuit.
In this case we are considering the quite low level…ma’s… that is required for a gas tube, so disregard the loading procedure as mentioned before in using a low wattage lamp substitution.
In the very, very end , if a “purist” replacement is not required, even a small hi intensity LED of the desired color could be utilized , with proper computations of aux power supply interfacing parts. With the total end result having a half life reliability factor of 4 eons.
73,s de Edd

:From all of your description as well as the dimensions, it certainly sounds like a neon, even with the enhancement of the electrodes surface area with the addition of a couple of square plates. The already specified American lamps do have a somewhat larger bulb profile than the dimensions that you have given. The darkening of the internals is also coincident with a neon lamp with some degree of use, however it is also apparent on a well used incandescent lamp. BUT this is assuming that you saw no evidence of the skimpier support structure for a filament ……but that is almost assuredly not the case with your reference to the HEAVIER electrodes with supplemental “plates”.
:One thing that you did not mention is if the end of the bulb profile is rounded off as is common, or is pulled to a small”tit’.
:Le Radio-Docteur seemed to have been right on it in the thought of the ?20 numerical designator, but that omission just might have been on the part of the bulb manufacturer and his marking , as neon or argon just doesn’t ionize and strikeover at a 20 V level.
:You still might take both an AC and DC voltage reading on the units wiring terminals when powered up to actually see what is present and being supplied to the lamp circuit.
:In this case we are considering the quite low level…ma’s… that is required for a gas tube, so disregard the loading procedure as mentioned before in using a low wattage lamp substitution.
:In the very, very end , if a “purist” replacement is not required, even a small hi intensity LED of the desired color could be utilized , with proper computations of aux power supply interfacing parts. With the total end result having a half life reliability factor of 4 eons.
:73,s de Edd
:

Edd,

Wonder where Chas went. I was going to send him the bulb. I have no need for it and after all what is a couple of 1st class stamps to help someone in a jam.

Radiodoc

Hello Radiodoc:

Apologies for unintended lack of response. I sent (or thought I did) an email to you through the forum email, after setting up the email account per prompts. I will try again.

Many Thanks

Chas

:Hello Radiodoc:
:
:Apologies for unintended lack of response. I sent (or thought I did) an email to you through the forum email, after setting up the email account per prompts. I will try again.
:
:Many Thanks
:
:Chas

Hi Chas,

You should get the lamp in 2 or 3 days.

Radiodoc

Charles: The power dissipation of a NE 51 lamp is about 1/20 of a watt. Perhaps this explains the strange marking. I agree with the others that 20 volts will not "fire" any neon or argon gas lamps. One thing you should look at is the presence of a current limiting resistor in series with the lamp. If it truly calls for a neon there will be at least a 50K resistance in series with it in your radio. :Thanks All for the replies:
:
:Unfortunately I cannot use the left-handed knobs for the Zenith. I checked the Brittanica Resource Directory on Zenith plastic case sets and it specifies that the C724L was sold to right-handed consumers only, due to the color of the cabinet. It further specifies that left-handed knobs may only be substituted if the cabinet is painted white and then has Rose designs applied. I do not intend to do that. As I have already invested heavily on the purchase of this radio (99 cents) I have no desire to do anything to decrease its value.
:
:As for the lamp for the JVC Nivico... I have the old bulb. The base is clearly stamped 20V, which is followed by three asian characters in an oval. The bulb measures 1 1/8" from tip of base to top of glass bulb, and the base is 3/8" in diameter. Inside the glass bulb there is a glass post with two wires in it. The wires come out of the top of the post and each wire is attached to a square "plate." The plates do not touch, and are not connected in any way. The inside of the glass bulb is pretty well smoked.
:
:The bulb mounts behind a red lens on the front of the radio, I would assume to light up when the radio is turned on. This is uneducated speculation on my part. Perhaps the illumination of this lamp indicates the approach of Godzilla, and if I plugged the radio in, turned it on, and dropped it in water it would destroy all the oxygen in the water thus eliminating any threat from large ocean creatures. As such, it is a valuable device to keep on hand, and my need for a good bulb should be painfully obvious.
:
:Was told it was a neon bulb by the clerk at a local lighting supply store. We went through all his catalogs and could not find a replacement. Have looked at several bulb sources on line with no success. Have called JVC and the rep there couldn't find any reference to a Model 88U radio.
:
:Seems like a quest into the unknown.
:
:Thanks Again-
:
:Chas