BQ041-22803 FUSE LAMP

8V 100 ma lamp fuse

Yaesu BQ041-22803
8V 100 MA Lamp Fuse Bulb

The Yaesu FT-747 and FT-757 Ft-757GX FT-757GXII radios employ a protection lamp on the input of the receiver section. This fuse is easily accessible by simply removing the bottom cover. It can be soldered to the existing leads without removing the RF board.

If any damaging voltage finds its way into the radio, the little grain of wheat bulb will open and save the front end of the receiver. Sometimes these bulbs open during electrical storms, even when the radio is turned "off". 

Static charges can build up on a wire antenna and that can open this fuse.  I have found that its a good idea to disconnect the antenna from the radio when its not in use. 

The Yaesu part number BQ041-22803 for these lamps, was discontinued long ago.  The 757GXII owners manual specifies the part as an 8V 100 ma lamp fuse.  I found some 8V 100 ma axial lamps that meet the specification, but the axial form factor is not ideal in this application.

As noted on several websites, any low current, grain of wheat type lamp, from 6 to 8 volts, is a suitable replacement, so long as it is not rated at more than 100 ma.  These are not easy to find.  If you do find one you end up paying a lot more for shipping than the bulbs are worth. 

I found some grain of wheat 6.5V / 68mA bulbs
that fit the bill for use as fuses and are just the right size. 
I have extras

If you need a replacement fuse bulb, contact me here.
I'll send you (2) for $8.25 postpaid while my supply lasts.

NOTE:  The bulbs I have work well as fuses
but they are under-rated for use in illuminating the S-meter, etc.

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Bill Patton, WY3A
West Chester, PA