Fisher 202 Futura Series receiver question

Discussion in 'Fisher' started by Tube Radio, Mar 6, 2017.

  1. Tube Radio

    Tube Radio Super Member

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    3,377
  2. mrphilco

    mrphilco AK Subscriber Subscriber

    Messages:
    402
    Location:
    Ferdinand, IN
    Yes, they will work fine.

    I used blue 31mm LED fuse lamps in my 202 Futura, and they really make that dial "pop". What a difference...like night and day.
     
  3. Tube Radio

    Tube Radio Super Member

    Messages:
    3,377
    Awesome.

    Will I need to run those on 8 volts or will 6.3 volts be ok?

    I originally used three green LEDs for the tuning meter as I didn't like the white and built a small voltage doubler circuit to power them with.

    I took that circuit and rebuilt it using 220uF caps and put heat shrink around the circuit so it could be set near where the output transistors are.

    Concerning the other 6 indicator bulbs, will warm white LEDs work for them?

    If I do need 8 volts for the LED fuse lamps I can use a 7809 with that doubler circuit then add a resistor in series.

    The bulbs currently in there are 6.3Vac 150mA, but I don't know if they are original.

    Here's how the receiver currently looks lit up, although the camera I used made the shades of the colors a good bit lighter.

    The dial pointer was made orange using a small piece of plastic from a neon indicator light that came from a defunct record player.

    [​IMG]
     
    Last edited: Mar 17, 2017
  4. mrphilco

    mrphilco AK Subscriber Subscriber

    Messages:
    402
    Location:
    Ferdinand, IN
    Those 8 volt LEDs will run very happily on 6.3 volts. The reverse is not true (don't ask how I know).

    As to warm white vs. blue, I think that comes down to user preference. It looks like Fisher was aiming for a blue dial, but incandescent lamps don't quite convey a pure blue dial. Blue LEDs provide a pure blue (and bright) display, making the numbers very easy to read. I did not try warm white LEDs in my 202, but I'm sure they would be just fine as well. Either will be brighter than the stock incandescents and will make the numbers easier to read.

    Interesting mod you made, changing the color of the tuning meter to green. It's different. I like it. I used bright white LEDs for mine. In fact I replaced all of the grain of wheat indicator lamps with 3mm LEDs; red for all except the tuning meter which, as I mentioned, are warm white.

    The 202 Futura is not a very powerful receiver, but that dial certainly looks good with LEDs!
     
  5. gadget73

    gadget73 junk junkie Subscriber

    Messages:
    32,928
    Location:
    Southern NJ
    Incandescent lamps through a blue filter usually comes out with a greenish color. The stock dash illumination on my Lincoln used that setup. Cool white LED gives a distinct blue color, blue LED gives an obnoxious blue. Warm white LED gives the stock greenish color but much brighter.
     
  6. Tube Radio

    Tube Radio Super Member

    Messages:
    3,377
    I've seen that effect using those blue bulb covers commonly used kin pinball machines. Produced a nice blue/green color when used with the edge lit dial of a Browning RV-32 FM tuner and the dial of my Magnavox CR-198C console.

    The dial of the 202 is a nice deep blue.

    I've seen pictures of the blue LEDs and never did like the look, but the cameras used could have made the shade of blue lighter than it really is in person. That said I've seen other blue LEDs in person and never quite liked the shade of blue used.

    Figured it was best to go with something that lit up similar to incandescent bulbs to keep the same look.

    The Fisher indeed isn't powerful at only 25 WPC, but it can go quite loud with efficient speakers.

    More than likely what I will do is replace the indicator lamps with warm white LEDs and connect two in series then use a resistor to make them about as bright as the other indicator lamps.

    What surprises me is this.

    The current of the three green LEDs in series is 420uA, yet they are bright. From what I remember these came from a christmas light set and most likely are 5 volt LEDs. At first I thought I had calculated wrong, but that is indeed the current.

    I used a simple voltage doubler to power them.

    Voltage doubler.png

    Figure on using that circuit to power all the lights once they are all LED and I can insert it between the power transformer and switch wafer that switches the various lights along with a 7809 regulator.

    I can then use resistors in series with the LEDs to get them at the proper brightness.

    That said it may be possible to use resistors and dispense with the regulator completely.

    The ground goes to one side of the lamp winding on the transformer. Suppose that winding wasn't grounded to reduce the chance of hum.
     
  7. Tube Radio

    Tube Radio Super Member

    Messages:
    3,377
    An update.

    Got the led lamps installed and they are bright enough on 6.3Vac.

    There is a problem though.

    The color of the dial changed from the blue it was to a more blue shade of blue.

    The current shade of blue looks like it is more of a whitish shade of blue or like it has some white in it.

    The original shade looked like it had a slight bit of green to it which made it more of a blue greenish color closer to blue.

    Not sure I exactly like the different color of the dial scale.

    That concerns me as I am afraid warm white LEDs for the other indicator lamps may alter their colors as well.

    I did remove the lamp holder panel for the dial lamps and used two LEDs and two incandescents and found the LEDs are more of a yellowish white color leaning more towards white, whereas the incandescents are more of a yellowish/orangish whitish color leaning more towards yellow/orange.
     
  8. gadget73

    gadget73 junk junkie Subscriber

    Messages:
    32,928
    Location:
    Southern NJ
    Probably a cooler white LED than the original bulb was. I had to use 2700K lamps to get stock coloring on the Lincoln. The add-on gauges I have used different base bulbs, and all I could get there were 3000K. Blue filters gave blue light, I needed green filters to get close to the stock green color. The dash bulbs with the blue filter give the proper greenish light. The higher the color temperature number, the more blue looking the light will end up.
     
  9. Tube Radio

    Tube Radio Super Member

    Messages:
    3,377
    Could it be that the 8 volt fuse lamps were brighter than the 6.3 volt fuse lamps which would make them more of a white color?

    The receiver does have a 2 amp fuse for all the indicator lamps so I wonder if 250mA fuse lamps were what was originally used?

    If this did use 250mA fuse lamps, could the 150mA lamps not being as bright have altered the shade of the dial scale?

    That would have made the dial brighter than what it was. Perhaps a previous owner could only get 150mA fuse lamps as I'm pretty sure the original lamps would not have lasted this long looking like they haven't seen much use unless the receiver sat for years unused.

    Would the cool blue version have been any better at keeping the original shade of blue?

    Only thing the specs don't say is the color temperature of the warm white LEDs
     
    Last edited: Mar 20, 2017
  10. gadget73

    gadget73 junk junkie Subscriber

    Messages:
    32,928
    Location:
    Southern NJ
    Without knowing what the original shade of blue was, its hard to say if cool white would do it. I can only speak from my experiences with car lighting, and I can tell you that cool white through a blue filter has a very distinct blue tint. If you want it more green, then cool white isn't going to do it. Incandescent lamps tend to be extremely warm on the color temp scale, somewhere around 2500K depending on input voltage and other particulars.

    Not impossible that the bulbs are original. One of the ones in my Fisher 600 is original, the other is an original used bulb from my parts unit. They're both over 50 years old.
     
  11. Tube Radio

    Tube Radio Super Member

    Messages:
    3,377
    I want to say the dial looked like this originally or real close to that. Best I could do with the photo app in Windows 10.

    Dial.png


    That said I seem to remember perhaps the dial of the 202 I had in my teens being a little brighter and more blue which might have been possible if 250mA bulbs were originally specified.

    Maybe I could get some green filter material and try it in front of the LEDs.

    The Fisher part number for the dial lamps is LM4031-2760051

    This picture is kind of blurry, but it shows how I remember the one I had as a teenager looking.

    [​IMG]

    From https://www.pinterest.com/pin/161707442840629470/

    It looks a bit brighter than the one I have now was.


    EDIT:

    Used the receiver at work a lot today and the more I look at the dial the more I realize that color blue is what I remembered the one I had as a teenager looking like only the LEDs seem to make the blue look more like it has a little white in it.
     
    Last edited: Mar 21, 2017
  12. Tube Radio

    Tube Radio Super Member

    Messages:
    3,377
    I had ordered some 3mm warm white LEDs and tried two in one of the indicators. The blue part of the indicator was not the same.

    Wondering what I was gonna do I thought and had an idea.

    Why don't I dissect the extra LED fuse lamp for the LEDs and use them.

    Tried that and the indicator now looks right.

    Gotta order another pack of those fuse lamps as I need 4 more of those LEDs which will require only one lamp as it has three and I still have the one from the lamp I already dissected. That will leave me four LED fuse lamps to use in something else or as spares should the ones in the Fisher ever fail which probnably won't happen in my lifetime.

    For the dial pointer I had tried one of those LEDs, but it made the pointer too yellowish looking. Thought about it and it hit me why don't I use an orange LED.

    I am gonna run everything on the voltage doubler with a 7809 regulator as using the regulator makes the calculations for the resistors much easier starting off with a known voltage.

    For the dial lights I measured the AC voltage to one of the sockets and ran one bulb on a DC voltage equal to the AC voltage then took a current reading so I could figure out the size of resistor necessary to drop the 9Vdc to the proper voltage. I thought of using just one resistor for all four lamps, but then thought if one lamp fails then that will put more voltage on the other lamps so I decided to use a resistor for each lamp.

    For the indicator I adjusted the voltage until the blue part was as bright as the blue of the dial.

    While doing that I noticed that the individual LEDs vary their current a lot for a small voltage change so using the regulator is indeed a good idea as the lamps won't change brightness if the line voltage changes.

    Now once everything is done should I leave the 2 amp fuse in place or go to a smaller fuse value?

    I'm amazed at how little current some of the LEDs require to be bright enough.

    The green LEDs for the tuning meter only draw around 420uA and are bright enough to properly light the meter. I used three in series as when I had done that once before on the one I had as a teen I only used two and the meter was darker towards the middle.

    I also noticed something. The brightness of the LEDs in those fuse lamps does affect the color somewhat at least far as the blue is concerned. Possibly as the LEDs get brighter their color temperature changes slightly.
     
  13. mrphilco

    mrphilco AK Subscriber Subscriber

    Messages:
    402
    Location:
    Ferdinand, IN
    I know that I am in the minority when it comes to the look of blue LEDs in receiver dials...but I don't care, I like how they look. I also like how they really brightened up the dial of my 202 Futura.

    The LED fuse lamps I used were plug and play, no voltage modifications needed.

    I did have to add dropping resistors in series with the LEDs I used for the other indicator lamps. The yellow I used for the dial pointer suits me. I used 3mm red for the red indicators including Stereo Beacon lamps, and bright white behind the tuning meter. I'm happy with it.
     
  14. Tube Radio

    Tube Radio Super Member

    Messages:
    3,377
    I look at it as everyone has their own preferences.

    I still think mine may have originally had 250mA fuse lamps in it as the dial was hard to read in all but a darker room and I'm sure it didn't come from the factory like that. Would have drawn 1A of current not including the meter lamps and dial pointer which could explain the 2A fuse used as with 150mA dial lamps perhaps only a 1A fuse would have been necessary.

    The warm white LEDs did get the dial closer in brightness and color to the one I remember having as a teenager.

    I regret disassembling it for parts as it had the optional wood trim which this one doesn't have.

    My dial lamps work good on the 6.12Vac they are being fed, although for the other LEDs I will run DC to them and figured it was easier to just use one voltage doubler with regulator and use resistors to provide the correct voltages for all the LEDs versus using a separate doubler for each LED since all the lights are switched on the input selector switch.

    I was on the fence about trying the blue LEDs for the dial, but had figured the warm white LEDs would keep the shade of blue closer to the original.

    I do have a small string of LED Christmas lights where 1/2 don't work so I might have an orange LED for the dial and if so I can figure out the necessary resistor to use in series with it.

    For securing the surface mount LEDs in the holes for the indicators I used a component lead in a U shape to join two together then soldered the two wires that supply power to the LEDs and used a dab of super glue where the wires are and also the component lead so that should I have to remove the LEDs it won't be very hard to do.

    Here's the latest schematic of the voltage doubler circuit.

    Voltage doubler 2.png



    EDIT:

    I found a 7805 regulator and looked online at how to make it put out 9Vdc. B+ for the LEDs is 9.10Vdc. I found a terminal strip I had and used that for the resistors for the dial lamps, dial pointer and tuning meter LEDs.

    The regulator is mounted to the main filter cap clamp using one of its screws. Didn't isolate the regulator from the chassis though as the transformer winding for the lighting is not connected to the chassis or any other ground.

    For the resistor that is in series with the indicator bulbs I removed one of the screws holding the terminal strip in place that has the connections for the indicator lamp wiring and used an insulated terminal stud. The resistor was put in the negative as the positive is what is switched by the function switch and that saved two resistors since only one function indicator is on at any time.

    Gotta take voltage readings tomorrow and update the schematic then I'll post here.

    Only need to buy a pack of 5 LED fuse lamps now to get three LEDs from them then install those and the conversion will be done.

    I did notice the B+ drops to nearly 12Vdc from 15Vdc when the dial lamps are on. Probably should have used larger caps in the voltage doubler, but the regulated voltage stays at 9.10Vdc so all is good.

    Everything is totally reversible so if a future owner wants to go back to incandescents it only requires removing a few components and putting back the wiring as it originally was.

    I did notice that the increase of 100mV did affect the voltages to the LEDs somewhat particularly the ones for the indicator which I sort of expected as once those warm white LEDs light up it doesn't take much of a voltage change to change the brightness a good bit.

    I would up using some resistors I had in my stash so I had to combine some, but they are 1% metal film.

    As seen on the schematic there's some oddball resistor values, but that was done to keep the LED voltage at that which provided the proper brightness when testing with a DC supply.

    I'll try and get some pictures of the installation tomorrow, but will have to take it out to my car as I cannot have a cellphone at work.
     
    Last edited: Apr 3, 2017
  15. Tube Radio

    Tube Radio Super Member

    Messages:
    3,377
    Here's some pictures of the LED mods.

    The voltage regulator and the power supply is in the black heat shrink under where the regulator is.

    [​IMG]

    Indicators

    [​IMG]

    Stereo indicator and meter LEDs

    [​IMG]

    Dial pointer

    [​IMG]

    Resistors

    [​IMG]
     
  16. Tube Radio

    Tube Radio Super Member

    Messages:
    3,377
    Here's the final schematic

    Voltage doubler 4-1.png

    The conversion is finished and the receiver looks good lit up.
     
  17. Tube Radio

    Tube Radio Super Member

    Messages:
    3,377
    Here's some pictures of the receiver lit up

    All colors are a little darker shade than what the camera shows.

    Interestingly this first picture the blue shows two distinct shades, but isn't really like that.

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]
     
  18. oldsansui

    oldsansui Active Member

    Messages:
    123
    Location:
    Sansui City Luebeck, Germany
    Good advice here, thank you.
    I have to replace the 2 stereobeam lamps and the 2 lamps for the meter below. What values are necessary?
     
  19. Tube Radio

    Tube Radio Super Member

    Messages:
    3,377
    The stereobeam lamps are two red LEDs from a LED christmas light string and just connect where the original bulbs did no dropping resistors necessary.

    The meter lamps I used were green LEDs from the same LED christmas light string only I used three in series to eliminate a dark spot in the middle of the meter.

    The dial pointer is a single orange LED from the same LED christmas light string.

    My advice is to do like I did and replace all lamps with LEDs, but if not just build the voltage doubler portion and use a 15K resistor in series with the three meter LEDs and adjust the resistance to suit the desired brightness and LEDs used. If you do replace all the lamps the resistor values can be adjusted to set the LED brightness to your liking just don't go over about 20mA for any of the LEDs

    Any color LED will work for the meter, but if you desire the original look warm white LEDs will work.

    What shade of blue does the dial on yours light up Also can you see if it uses 150mA or 250mA fuse lamps?

    Mine originally lit up a lighter shade of blue which almost looked like it was faded and had 150mA fuse lamps and was hard to see in a lit room, but I seem to remember the one I had in my teens lighting up a darker shade of blue and was lit up brighter.

    With the LED fuse lamps I get a darker shade of blue, but still don't think it is as dark a shade of blue as I remember, although it is acceptable.

    Also concerning the lights if you replace them all with LEDs and yours has a fuse in the lighting circuit it would be good to swap the 2A fuse for a 1A fuse since the current draw will be much less, although it really isn't necessary.

    It is possible to use a 7809 instead of the 7805 and omit the resistors on the regulator. I only used a 7805 because that's what I had on hand.
     
    oldsansui likes this.

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