Motorola Pageboy Charger NLN6432B

[joekc4g]

Can anyone tell me what type of lamp was used in the Pageboy Charger. I'm talking the original Pageboy and the charger model number is NLN6432B. The charger had a lamp on the top that lit when the unit was charging. The lamp had a bayonet type base similar to a #47 - but - I'm pretty sure that it was not a #47. Could it have been a NE51 lamp? It has a bayonet base also. The charger will not operate without the lamp so, it would seem that the lamp is part of the charging circuit.

[Al]

I don't know the specifics of the pageboy charger, but if the lamp that you mentioned was part of the low voltage charging circuit it wouldn't be a neon lamp. Neons don't begin conducting current until the terminal voltage exceeds 90 VAC, and then only a relatively(compared to an incandescent) small current initially. Most neons can be identified by two physically separated electrodes as opposed to a filament in an incandescent. And they glow orange when the strike voltage is exceeded.

[joekc4g]

Yep - I understand. The thing is - I don't have a manual and the charger belongs to a friend. I haven't had a chance to look at it yet so I'm not sure if it's in the AC input side or what. I do know that he tried to put a #47 in there. He said that it glowed very dimly and the charger had very little output voltage (I'm assuming less that the nominal 3.9 volts). Anyhow, it would sure be good if I could find a manual or a parts list. Thanks for your input.

[k2hz]

I can't find the lamp info for that specific charger but similar chargers of that era for portables like the HT200 used an incandescent lamp as the current limiting device. Some lamp types used were 756, 1819 & 1829 with the desired charge rate apparently determining the lamp type used.

[joekc4g]

K2HZ, Thanks for the input. That may be a good clue.

[joekc4g]

Does anyone else have an idea what this lamp type may be? Or - does anyone have a schematic diagram or a parts list for the Pageboy I charger, model NLN6432B? Thanks for taking a look.

[k2hz]

I believe the lamp is in series with the battery to act as a simple current regulator. If so, voltage of the lamp plus the voltage of the battery should be slightly greater than the open circuit output voltage of the charger and the current rating of the lamp should be
slightly greater than the maximum charging current.

This should give you a clue to the voltage and current specs of the lamp. If you do find a parts list with a Motorola part number I may be able to cross reference it. I have some old Motorola parts books that list lamps for various equipment of that era. One does list the NLN6432B but for some reason does not list the lamp although the same list has lamp data for some other chargers.

If you can make a good guess at the lamp voltage, you might try a lamp that is close in its specs and see if it has reasonable brightness.
If too bright or charging current is excessive, you need a higher voltage. If dim and battery not charging you need a lower voltage lamp.

If the lamp is not in series with the battery then my theory is no good.

[joekc4g]

K2HZ, thanks. Yes, I agree with your theory. I'll need to get a good look at the charger to confirm it, though. I'm going to try to do that one day this week. If we're correct, then the choice of lamp wouldn't be real critical. I mean - I think we would be looking for the charger to produce an output voltage a bit higher than the nominal voltage of the battery. And - we're looking to have enough current to burn the lamp at something like a normal brightness. I have an old Motorola Parts & Data Handbook but I have the same issue you have in that it doesn't tell the part number of the lamp.

[mike38015]

No sure if this will help but there are 2 pageboy chargers on eBay:

http://www.ebay.com/itm/Motorola-Pagebo ... Sw-7RVByaL. - $18.99

http://www.ebay.com/itm/Motorola-Pagebo ... SwwbdWIb6e - $6.00

And a manual:

http://www.ebay.com/itm/Motorola-Manual ... SwGotWsTcM -$15.00.

Might be worth a try