Icom IC-28H Backlight Replacement
 

My Icom IC-28H has gone dark. Looks like both lamps are gone. The
schematic lists these lamps as HRS-7219A-G40. I found a couple of
places that had minimum orders of $100 and $300 respectively. That's
out. I read a message on eham.net where a ham had replaced these
lamps with amber LED's and appropriate resistors. Anyone done this?
Other options?

Dick - W6CCD

Try Radio Shack, as they had some grain of wheat bulbs at various voltages.

Bob N9LVU

Dick wrote:
My Icom IC-28H has gone dark. Looks like both lamps are gone. The
schematic lists these lamps as HRS-7219A-G40. I found a couple of
places that had minimum orders of $100 and $300 respectively. That's
out. I read a message on eham.net where a ham had replaced these
lamps with amber LED's and appropriate resistors. Anyone done this?
Other options?

Dick - W6CCD

My problem is I had to disassemble the radio so far to get to the back
of the lamps, I can't run it to check the voltage. The lamps are
driven by an automatic dimmer circuit, so can't just trace the source.
Would like to see a data sheet on the lamps, but doesn't seem to be
available. I saw one reference to Intersil as the manufacturer, but
it's not listed on their website.

Dick

On Fri, 18 Mar 2005 13:59:07 -0600, Robert Kubichek
wrote:

Try Radio Shack, as they had some grain of wheat bulbs at various voltages.

Bob N9LVU

Dick wrote:
My Icom IC-28H has gone dark. Looks like both lamps are gone. The
schematic lists these lamps as HRS-7219A-G40. I found a couple of
places that had minimum orders of $100 and $300 respectively. That's
out. I read a message on eham.net where a ham had replaced these
lamps with amber LED's and appropriate resistors. Anyone done this?
Other options?

Dick - W6CCD

If you look at the schematic, you will see that there is 11.5v supplied
to the lamps for the display, ANY grain of wheat lamp rated for 12-15v
will work. Radio shack does sell them, most older Icoms IC229H ect use them.

Bob N9LVU

Dick wrote:
My problem is I had to disassemble the radio so far to get to the back
of the lamps, I can't run it to check the voltage. The lamps are
driven by an automatic dimmer circuit, so can't just trace the source.
Would like to see a data sheet on the lamps, but doesn't seem to be
available. I saw one reference to Intersil as the manufacturer, but
it's not listed on their website.

Dick

On Fri, 18 Mar 2005 13:59:07 -0600, Robert Kubichek
wrote:


Try Radio Shack, as they had some grain of wheat bulbs at various voltages.

Bob N9LVU

Dick wrote:

My Icom IC-28H has gone dark. Looks like both lamps are gone. The
schematic lists these lamps as HRS-7219A-G40. I found a couple of
places that had minimum orders of $100 and $300 respectively. That's
out. I read a message on eham.net where a ham had replaced these
lamps with amber LED's and appropriate resistors. Anyone done this?
Other options?

Dick - W6CCD

I sure don't see that Bob. The lamps are driven off the collector of
Q12. This voltage varies in accordance with the light received by R3.
I don't see any reference to voltages at all anywhere in that
circuit..

Dick

On Fri, 18 Mar 2005 15:53:06 -0600, Robert Kubichek
wrote:

If you look at the schematic, you will see that there is 11.5v supplied
to the lamps for the display, ANY grain of wheat lamp rated for 12-15v
will work. Radio shack does sell them, most older Icoms IC229H ect use them.

Bob N9LVU

Dick wrote:
My problem is I had to disassemble the radio so far to get to the back
of the lamps, I can't run it to check the voltage. The lamps are
driven by an automatic dimmer circuit, so can't just trace the source.
Would like to see a data sheet on the lamps, but doesn't seem to be
available. I saw one reference to Intersil as the manufacturer, but
it's not listed on their website.

Dick

On Fri, 18 Mar 2005 13:59:07 -0600, Robert Kubichek
wrote:


Try Radio Shack, as they had some grain of wheat bulbs at various voltages.

Bob N9LVU

Dick wrote:

My Icom IC-28H has gone dark. Looks like both lamps are gone. The
schematic lists these lamps as HRS-7219A-G40. I found a couple of
places that had minimum orders of $100 and $300 respectively. That's
out. I read a message on eham.net where a ham had replaced these
lamps with amber LED's and appropriate resistors. Anyone done this?
Other options?

Dick - W6CCD

In the sevice manual, the junction of R77-R78-Q12 is 11.5v and this goes
out to the lamps.

Bob N9LVU

Dick wrote:
I sure don't see that Bob. The lamps are driven off the collector of
Q12. This voltage varies in accordance with the light received by R3.
I don't see any reference to voltages at all anywhere in that
circuit..

Dick

On Fri, 18 Mar 2005 15:53:06 -0600, Robert Kubichek
wrote:


If you look at the schematic, you will see that there is 11.5v supplied
to the lamps for the display, ANY grain of wheat lamp rated for 12-15v
will work. Radio shack does sell them, most older Icoms IC229H ect use them.

Bob N9LVU

Dick wrote:

My problem is I had to disassemble the radio so far to get to the back
of the lamps, I can't run it to check the voltage. The lamps are
driven by an automatic dimmer circuit, so can't just trace the source.
Would like to see a data sheet on the lamps, but doesn't seem to be
available. I saw one reference to Intersil as the manufacturer, but
it's not listed on their website.

Dick

On Fri, 18 Mar 2005 13:59:07 -0600, Robert Kubichek
wrote:



Try Radio Shack, as they had some grain of wheat bulbs at various voltages.

Bob N9LVU

Dick wrote:


My Icom IC-28H has gone dark. Looks like both lamps are gone. The
schematic lists these lamps as HRS-7219A-G40. I found a couple of
places that had minimum orders of $100 and $300 respectively. That's
out. I read a message on eham.net where a ham had replaced these
lamps with amber LED's and appropriate resistors. Anyone done this?
Other options?

Dick - W6CCD

Ah ha! You have a service manual. Now I understand.

Dick

On Fri, 18 Mar 2005 17:36:28 -0600, Robert Kubichek
wrote:

In the sevice manual, the junction of R77-R78-Q12 is 11.5v and this goes
out to the lamps.

Bob N9LVU

Dick wrote:
I sure don't see that Bob. The lamps are driven off the collector of
Q12. This voltage varies in accordance with the light received by R3.
I don't see any reference to voltages at all anywhere in that
circuit..

Dick

On Fri, 18 Mar 2005 15:53:06 -0600, Robert Kubichek
wrote:


If you look at the schematic, you will see that there is 11.5v supplied
to the lamps for the display, ANY grain of wheat lamp rated for 12-15v
will work. Radio shack does sell them, most older Icoms IC229H ect use them.

Bob N9LVU

Dick wrote:

My problem is I had to disassemble the radio so far to get to the back
of the lamps, I can't run it to check the voltage. The lamps are
driven by an automatic dimmer circuit, so can't just trace the source.
Would like to see a data sheet on the lamps, but doesn't seem to be
available. I saw one reference to Intersil as the manufacturer, but
it's not listed on their website.

Dick

On Fri, 18 Mar 2005 13:59:07 -0600, Robert Kubichek
wrote:



Try Radio Shack, as they had some grain of wheat bulbs at various voltages.

Bob N9LVU

Dick wrote:


My Icom IC-28H has gone dark. Looks like both lamps are gone. The
schematic lists these lamps as HRS-7219A-G40. I found a couple of
places that had minimum orders of $100 and $300 respectively. That's
out. I read a message on eham.net where a ham had replaced these
lamps with amber LED's and appropriate resistors. Anyone done this?
Other options?

Dick - W6CCD

You can get one for free too;
http://mods.dk/view.php?ListManuals=icom

Bob N9LVU


Dick wrote:
Ah ha! You have a service manual. Now I understand.

Dick

On Fri, 18 Mar 2005 17:36:28 -0600, Robert Kubichek
wrote:


In the sevice manual, the junction of R77-R78-Q12 is 11.5v and this goes
out to the lamps.

Bob N9LVU

Dick wrote:

I sure don't see that Bob. The lamps are driven off the collector of
Q12. This voltage varies in accordance with the light received by R3.
I don't see any reference to voltages at all anywhere in that
circuit..

Dick

On Fri, 18 Mar 2005 15:53:06 -0600, Robert Kubichek
wrote:



If you look at the schematic, you will see that there is 11.5v supplied
to the lamps for the display, ANY grain of wheat lamp rated for 12-15v
will work. Radio shack does sell them, most older Icoms IC229H ect use them.

Bob N9LVU

Dick wrote:


My problem is I had to disassemble the radio so far to get to the back
of the lamps, I can't run it to check the voltage. The lamps are
driven by an automatic dimmer circuit, so can't just trace the source.
Would like to see a data sheet on the lamps, but doesn't seem to be
available. I saw one reference to Intersil as the manufacturer, but
it's not listed on their website.

Dick

On Fri, 18 Mar 2005 13:59:07 -0600, Robert Kubichek
wrote:




Try Radio Shack, as they had some grain of wheat bulbs at various voltages.

Bob N9LVU

Dick wrote:



My Icom IC-28H has gone dark. Looks like both lamps are gone. The
schematic lists these lamps as HRS-7219A-G40. I found a couple of
places that had minimum orders of $100 and $300 respectively. That's
out. I read a message on eham.net where a ham had replaced these
lamps with amber LED's and appropriate resistors. Anyone done this?
Other options?

Dick - W6CCD

Thanks a bunch Bob! I rarely check the DK site for service manuals
because it seems they never have the one I want. This time they do!

Dick - W6CCD

On Sat, 19 Mar 2005 08:53:55 -0600, Robert Kubichek
wrote:

You can get one for free too;
http://mods.dk/view.php?ListManuals=icom

Bob N9LVU

Try part number 606-CM7219 from mouser.com, $0.35 each.

Ron - K0QVF

Dick wrote:

My Icom IC-28H has gone dark. Looks like both lamps are gone. The
schematic lists these lamps as HRS-7219A-G40. I found a couple of
places that had minimum orders of $100 and $300 respectively. That's
out. I read a message on eham.net where a ham had replaced these
lamps with amber LED's and appropriate resistors. Anyone done this?
Other options?

Dick - W6CCD

Thanks. I had found that lamp in the Mouser catalog. However, the
last time I applied power to the IC-28H, one of the lamps came back to
life. When I observe it from the backside of the circuit board, the
lamp has a definite green glow. I assume this is what gives the green
look to the display. I read a message from one person who used amber
LED's to give it an amber display. This leads me to conclude that the
color of the lamp light is what determines the color of the display.
I have not seen any 7219 lamps on the Internet that are green. Still
looking.

Dick

On Thu, 31 Mar 2005 16:50:51 -0600, Ron wrote:

Try part number 606-CM7219 from mouser.com, $0.35 each.

Ron - K0QVF

Dick wrote:

My Icom IC-28H has gone dark. Looks like both lamps are gone. The
schematic lists these lamps as HRS-7219A-G40. I found a couple of
places that had minimum orders of $100 and $300 respectively. That's
out. I read a message on eham.net where a ham had replaced these
lamps with amber LED's and appropriate resistors. Anyone done this?
Other options?

Dick - W6CCD

In article ,
Dick LeadWinger wrote:

Thanks. I had found that lamp in the Mouser catalog. However, the
last time I applied power to the IC-28H, one of the lamps came back to
life. When I observe it from the backside of the circuit board, the
lamp has a definite green glow. I assume this is what gives the green
look to the display. I read a message from one person who used amber
LED's to give it an amber display. This leads me to conclude that the
color of the lamp light is what determines the color of the display.
I have not seen any 7219 lamps on the Internet that are green. Still
looking.

How about using a standard bulb (as in the Mouser catalog) and giving
it a light coat of green nail polish? A light-green LED with series
dropping resistor might also give you the desired hue.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

On Fri, 01 Apr 2005 00:57:17 -0000, (Dave Platt)
wrote:

In article ,
Dick LeadWinger wrote:

Thanks. I had found that lamp in the Mouser catalog. However, the
last time I applied power to the IC-28H, one of the lamps came back to
life. When I observe it from the backside of the circuit board, the
lamp has a definite green glow. I assume this is what gives the green
look to the display. I read a message from one person who used amber
LED's to give it an amber display. This leads me to conclude that the
color of the lamp light is what determines the color of the display.
I have not seen any 7219 lamps on the Internet that are green. Still
looking.

How about using a standard bulb (as in the Mouser catalog) and giving
it a light coat of green nail polish? A light-green LED with series
dropping resistor might also give you the desired hue.

I have been thinking about trying the amber LED's. I also sent an
e-mail to Icom to see what they can tell me.

Dick

On my IC-28H there are green boots over clear lamps. Just take the boot
off the old lamps and put them on the new ones.

Ron - K0QVF

Dick wrote:
On Fri, 01 Apr 2005 00:57:17 -0000, (Dave Platt)
wrote:


In article ,
Dick LeadWinger wrote:


Thanks. I had found that lamp in the Mouser catalog. However, the
last time I applied power to the IC-28H, one of the lamps came back to
life. When I observe it from the backside of the circuit board, the
lamp has a definite green glow. I assume this is what gives the green
look to the display. I read a message from one person who used amber
LED's to give it an amber display. This leads me to conclude that the
color of the lamp light is what determines the color of the display.
I have not seen any 7219 lamps on the Internet that are green. Still
looking.

How about using a standard bulb (as in the Mouser catalog) and giving
it a light coat of green nail polish? A light-green LED with series
dropping resistor might also give you the desired hue.


I have been thinking about trying the amber LED's. I also sent an
e-mail to Icom to see what they can tell me.

Dick

On Thu, 31 Mar 2005 18:05:51 -0700, Dick LeadWinger wrote:

On Fri, 01 Apr 2005 00:57:17 -0000, (Dave Platt)
wrote:

In article ,
Dick LeadWinger wrote:

Thanks. I had found that lamp in the Mouser catalog. However, the
last time I applied power to the IC-28H, one of the lamps came back to
life. When I observe it from the backside of the circuit board, the
lamp has a definite green glow. I assume this is what gives the green
look to the display. I read a message from one person who used amber
LED's to give it an amber display. This leads me to conclude that the
color of the lamp light is what determines the color of the display.
I have not seen any 7219 lamps on the Internet that are green. Still
looking.

How about using a standard bulb (as in the Mouser catalog) and giving
it a light coat of green nail polish? A light-green LED with series
dropping resistor might also give you the desired hue.

I have been thinking about trying the amber LED's. I also sent an
e-mail to Icom to see what they can tell me.

Dick

I got my answer back from Icom. Answers the question about the green
lamps.

Dick

Good Morning.....

Thanks for your e-mail.

The lamps are clear in color. The display color comes from the filter
that is behind the display. The stocking part number for the lamps
is: 5080000130. You can purchase them from our parts department.
Their e-mail address is: or you can telephone
them at: 425-454-8155. Hope this will help.

Best Regards;

Mike Hilton
Technical Support Representative

ICOM America, Inc.
2380 116th Ave. NE
Bellevue, WA 98004
Ph. (425) 454-7619
Fax (425) 637-8417
www.icomamerica.com

On Thu, 31 Mar 2005 20:52:54 -0600, Ron wrote:

On my IC-28H there are green boots over clear lamps. Just take the boot
off the old lamps and put them on the new ones.

Ron - K0QVF

A follow-up to my original post. I purchased the lamps from Mouser as
was suggested earlier. I bought 10 because I couldn't see paying
postage on $.58 worth of lamps. Now I have some spares.

As Ron said, the green comes from little, vinyl boots that the lamps
fit into. Once you get the old lamps out, you just carefully peel the
boots off. Replacing the lamps is easy as the pads are large and easy
to solder to. The hard part is in taking the head off the radio.
There are numerous plugs that have to come out so you can get access
to the backside of the display PCB. Be careful when you unplug them
as there are two sockets for several of them. You want to get the
plugs back into the correct sockets. I'm back in business with full
display lighting. Thanks everyone for the suggestions.

73, Dick - W6CCD