Browning Mark 4A PITA solution. Another wacky widget.

So, here is a so-called "feature" of the Browning Mark 4A transmitter. An illuminated status light to tell you which way the pointer on the Mode switch knob is pointing. As if you can't tell that at a glance. But the Mark 3 had them, so I suppose this model had to, as well.



Key the mike and you get the illuminated "On The Air" that was in the Mark 3 receiver. I guess thay had to include this somehow.



But the mechanical layout behind it is a pure aggravation. Small incandescent lamps with frog-hair thin lead wires are captive inside a white plastic reflector. Those wires hold the circuit board in place that connects the transmitter's wiring harness to the six bulbs. A pretty shaky proposition that nearly always has one or more bulbs with a snapped wire.



I should include some pics of hand-installed LEDs, mobile-radio pigtail lamps and other improvised fixes. Didn't find any on file.

Pretty ugly, anyway.

So enter another way to save labor on a PITA part of the job. Could just say "tough" to the customer and invite him to fix his own stupid lights. But if the radio comes with a feature, they will want it to work. Besides, telling a customer he can't have something is not generally considered the straight road to business success.



This board still takes labor to build, and some time if you want all the LEDs standing up straight at the right height.

But it saves time where it counts, getting the radio ready to send back home.

The flat-front LEDs diffuse the light well enough to prevent a bright spot at the center of the legends.

Got the pc board layout to line up the LEDs with the molded reflector. The friction holds this one pretty well. A dab of hot snot wouldn't hurt it.



Labeling the hole where each of 5 wires will solder to it works best when the wire colors haven't faded too badly.



This one might or might not prove popular on Ebay. Only one way to tell. Gotta build some more of them, first.

73

Andy, I used ExpressPCB. Their CAD is free, downloaded from http://www.expresspcb.com

When I first started using their service in 1999, there were not a lot of circuit-board fabs available online. They were the first one I stumbled across. Until then, you would snail-mail a floppy with your CAD files on it to a PCB vendor.

Now you have numerous choices, both in the USA, China and elsewhere. All of them are cheaper than ExpressPCB, based in Oregon, USA. Well, the offshore choices are cheaper.

All of those accept the "standard" file formats, a Gerber layout file, and an Excellon drill file. Standard PCB CAD software produces these file formats.

But ExpressPCB's software produces an output file in a proprietary format that you upload to their server to place your order. Haven't found an alternate vendor who accepts their CAD file format.

I keep getting advice to use the cheaper services, but I would have to switch CAD programs, and redraw all the boards we buy now.

I tend to stick with a tool that works, rather than try new ones. Even if they are cheaper.

Only bought a dozen of these. One of ExpressPCB's services is a fixed-size 2.5 by 3.8-inch board, three of them for 80 bucks, depending on shipping. I can get four of these LED boards on one of those, for a total of 12 once they are cut apart.

This reduces risk. If a new board has a fatal flaw, you don't want to have to ditch more junk boards than you have to.

Good chance the next batch of them will be 50 or 100 pieces. It would get combined with other small boards onto a larger one and ordered that way. Once they're sheared apart, the unit cost gets more affordable.

I have never had a problem with their quality, so that's worth something all by itself.

73

Well, if you have some REAL money for making your own pcbs, these guys have the stuff to do it.

https://www.lpkf.com/products/rapid-pcb-prototyping/index.htm

I have always considered their stuff to be in the "If you have to ask" price category. But they have been advertising the desktop pcb router in the engineering mags for years, now.

Probably not economical for production, though.

73