KT-7500 Dial and Meter Lamps Replacement

IndicaNights

IndicaNights

New Member
Great news I Finally scored a nice Kenwood KT 7500 tuner from ebay at a decent price $70.00 with shipping , so i was pretty happy when it arrived today, got it all plugged in and no lights in meters or dial :cry::cry::cry:.......so after some reading on da web i make a phone call to radio :yes:shack:yes:.....The Shack guy told me he dont have any 8 v 300 ma bulbs wich is what the tuner has in it from the factory, all he has is 6 v and 12 volt in stock. And he explains to me the 6 volt will burn bright and the burn out quickly and the 12 will be a lil dimmer cause you only have 8 volts goin through it, but there a cool lookin Green so i grabbed em wondering if they would work :scratch2: you see i dont tinker with inside of electronics much but i did get this tuner after reading it was a excellent tuner to do mods on. Well the bulbs were easy enuff to swap out:thmbsp::yes: Now i just hope they keep workin and dont goof nuthin else up, but they should be fine till i get some 8 volt lamps or maybe i will just leave em like this, the pics make them look brighter than what they really are but is ok i like the soft green look :thmbsp: it's kinda cool , Just thaught id pass on the info and pics maybe it will help some one out there. Im very pleased with the new tuner.
 

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I just relamped the KT7300 last nite. I used the Rat Shack 272-1133 7.5 220ma bulbs and it came out perfect. I used pliers to score the side of the screw base (File would have worked better but I didn't have one handy) Used my soldering iron to bleed a little solder on the side and softened the bottom contact. One two three four and it was done. Slip right back into the rubber holders and back in. I'm not the best with a soldering iron, but this was a breeze and the ratings of the bulbs are well within range. The light level is perfect (IMHO) From your pictures it looks like yours should be the same. :thmbsp:
 
The stock bulbs are overvolted anyway, so I would not expect a 7.5V lamp to last all that long.

The perfect replacement is a #192 bulb... 13V, 330mA. Draws about 230mA @ 8V, and will last for many years at the lower voltage in the Kenwood tuners.
 
EchoWars said:
The stock bulbs are overvolted anyway, so I would not expect a 7.5V lamp to last all that long.

The perfect replacement is a #192 bulb... 13V, 330mA. Draws about 230mA @ 8V, and will last for many years at the lower voltage in the Kenwood tuners.
Click to expand...

Thanks Glenn,
I just had mine re-bulbed last year and they are Out already :no:
 
I have used fingernail polish on a couple of mine with no ill effects The Big K has quiet a variety and to get just the right colouring, I have put it on.. then used nail polish remover on a paper towel to wipe some of it off and leave just a thin coating. Let completely dry before putting in. On the meter lights of my TU317 I used a really deep royal blue and it gives the a cool look. I will likely go back in and put them back to the lite greenish turquoise they were but it was a fun experiment.
 
  • Pebeo Vitrail Paint, Aqua Green is a stained glass (stain/paint) other colors available. recommended under 60watt incandescent.
  • .
    just incase anyone else comes back here.
    I also found some green bulbs at www.bulbtown.com looks like they may also be close enough.
    194G (the 194 bulbs draw a little less current than the 192) other colors are also available

    .
    from what I understand the led's have diodes so it doesn't matter which way you plug them in on a car (DC) but the power in the kenwood is ac. they sell a lot of led kits on ebay. don't know how long they hold up though? or how well this one would deal with the voltage drop
    192g.jpg
 
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Hi all - I just bought a minty KT 7500.

Tested nicely with just a piece of wire for antenna. 5 gang tuner. Performance seems similar to my Pioneer TX 9500 II

Dial lamps are out...so are the meter lamps. The 3 small red led's do work.

Took the cover off and took off the face plate. The bulbs for meters look very accessable, but I'm not seeing the dial lamps like I hope I would.

So my question is....how do you get to those lamps? I'm trying to disassemble as little as possible...not the best tech skills...lol.

Thanks - Jeff
 
On the KT-5500 the lamps are in silicone rubber holders that friction fit into the faceplate. Wired in series, and one of them is for the meters.

I replaced mine with bayonet base warm white LEDs. The originals are crimped onto the wires, you need to push the holders back to expose the crimp, cut it off, and solder the new lamp (LED or incandescent) to the wires and push it back into the holder.

KT-7500 might be different, but probably not.
 
HPMguy said:
On the KT-5500 the lamps are in silicone rubber holders that friction fit into the faceplate. Wired in series, and one of them is for the meters.

I replaced mine with bayonet base warm white LEDs. The originals are crimped onto the wires, you need to push the holders back to expose the crimp, cut it off, and solder the new lamp (LED or incandescent) to the wires and push it back into the holder.

KT-7500 might be different, but probably not.
Click to expand...

Hmm...I didn't see anything like that for the dial lamps. The metal faceplate came off easily....nothing was attached to it.

Like I said, meter bulbs can be seen easily .... they are directly behind the meters. I haven't futzed with them yet, but those should be pretty easy to replace.
 
Looked up the service manual for a KT-7500. Meter lamp is at the top of an acrylic light pipe, take the two screws out pull the bracket back. No schematic so it's hard to tell, but there are two pilot lamps listed in the parts list, at a guess they will be in series with the meter lamp. Probably again in an acyrlic light pipe in rubber sockets under that metal bracket somewhere.

A schematic would help, eh?
 
HPMguy said:
Looked up the service manual for a KT-7500. Meter lamp is at the top of an acrylic light pipe, take the two screws out pull the bracket back. No schematic so it's hard to tell, but there are two pilot lamps listed in the parts list, at a guess they will be in series with the meter lamp. Probably again in an acyrlic light pipe in rubber sockets under that metal bracket somewhere.

A schematic would help, eh?
Click to expand...

Ahh. So the meter lamps might be in series with the dial backlights? And since the meter lamps are not working, then the backlights won't work either? Sounds like I need to dig a little deeper. Thanks - what you said makes sense. I saw the service manual on line....not a schematic though.
 
What you are looking for is the circuit for the lamps -- they are a curly line in a circle, indicating a filament. Usually label "PL" by Kenwood for pilot lamp.

Usually an un-rectified AC line from near the transformer, often with a big resistor (2W) in circuit to reduce the voltage to 12V, but not always. Should be three of them, and if they are all on a single line, with the line going from one to the next, they are in series. Ocassionally the lamps will have a half wave (single diode) rectifier in line with a capactitor.
 
HPMguy said:
What you are looking for is the circuit for the lamps -- they are a curly line in a circle, indicating a filament. Usually label "PL" by Kenwood for pilot lamp.

Usually an un-rectified AC line from near the transformer, often with a big resistor (2W) in circuit to reduce the voltage to 12V, but not always. Should be three of them, and if they are all on a single line, with the line going from one to the next, they are in series. Ocassionally the lamps will have a half wave (single diode) rectifier in line with a capactitor.
Click to expand...

Ahh- yes I think I saw that PL circuit in the schematic. So if they're in line, if one goes out they all go out...like Christmas lights.

Thanks again for answering my remedial questions.
 
Might be under the metal cover over the dial cord. Saw some replacement LEDs on eBay, they look like they just push into a socket. Could also be on the bottom of the dial, not the top.

Yes, they are very likely in series, and I'd replace all of them with warm white LEDs. The ones I got for the KT-5500 look very very similar to the incandescent lamps, and I'll not have to replace them again -- the original bulbs lasted more than ten years, found them open after 30 more, and I don't expect to be around in 40 more years.
 
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