Maverick ET-73 Mod

JDNC · October 12, 2009, 03:24:15 AM

I came across LilSmoke's posting a couple of days ago in reference to the mod for the ET-73. I read all the posting on the subject and as I am an inactive ham operator and my major in college was in electronics (that was never put to use) I couldn't resist this mod. I had tested the range of my ET-73 due to the fact I recommended one to one of my friends and he was complaining of no range. I found with line of sight my range was max at 100 feet and at the fringe. As you can see I really didn't have a problem as some have reported but inside my house it will drop out at about 40 ft through the house. Well to the mod...Most rf signals at high freq are absorbed by surrounding objects and antenna's work better uninsulated (paint,plastic covering etc.) so I used an antenna off an old receiver that used a rf remote. I epoxied a small tube in the top and soldered a small wire (1 1/2") to the tube and circuit board. This allows removal of the antenna for storage. Oh..yeah I bridged the two pads left of the wire on the board. Range is amazing. Line of sight 390ft!

As for myself..I don't recommend messing with the transmitter as it's tuned for 433mhz and adding a wire might cause more problems that it's worth. Oh..I cut the antenna at 5.5" as the wire I added was a little over an inch. I could cut it to 5 for a total length (wire & antenna) of 6.5 but I don't think I will.

JDNC · October 12, 2009, 03:29:02 AM

I forgot to mention..the range of 390ft is as far as I've tested. I ran out of range this day as I was at the birm on my gun range. I couldn't find an area at home outside where I could lose the signal...amazing!

squirtthecat · October 12, 2009, 06:42:18 AM

Nice... Can you get a pic of the inside where you soldered it all together? I need to do that with mine.

Quarlow · October 12, 2009, 06:46:39 AM

Nice mod JD Could you use a telescoping antenna. for that also.

Hopefull Romantic · October 12, 2009, 11:22:28 AM

Quote from: squirtthecat on October 12, 2009, 06:42:18 AM

Nice... Can you get a pic of the inside where you soldered it all together? I need to do that with mine.

yes enquiring minds wanna know.

HR

JDNC · October 12, 2009, 12:09:53 PM

LilSmoke has a thread with the mod and pictures of the soldering points. I just installed a different antenna. As for a telescopic anntenna..I don't think there is enough room inside. Basically with the mod you just solder a wire to the board, cut it at 6.5 inches and drill a hole in the case of the unit and route the wire through.

JD

JDNC · October 12, 2009, 12:16:40 PM

Oh..I forgot to say the way I tested it was warming the temp probe of the transmitter so I could see changes as I walked around. I did check it at 400ft with the receiver inside the house..but no dice. It couldn't pickup at that distance. I didn't have time to check to see what range I could get leaving the receiver in the house at different ranges, but I will later.

squirtthecat · October 12, 2009, 01:32:49 PM

Here is the thread he was talking about..

http://www.susanminor.org/forums/showthread.php?t=571

squirtthecat · October 12, 2009, 01:39:43 PM

So you hit all three of those little pads, like so? Then up and out the top?

(forgive my crude MS Paint freehand skills)

smokeitall · October 12, 2009, 01:43:42 PM

Hey Squirt if you put a big enough antenna on it I could see your IT over here is STL ;D
SIA

squirtthecat · October 12, 2009, 01:49:29 PM

Quote from: smokeitall on October 12, 2009, 01:43:42 PM
Hey Squirt if you put a big enough antenna on it I could see your IT over here is STL ;D
SIA

:D

JDNC · October 12, 2009, 02:32:10 PM

Squirtthecat,

Yep, all three pads and out the top! Based on what I've read..some report that they can't tell much difference after the mod, but most do. I really didn't think I would see much myself (but what the heck) and was very much pleased to find 4 times the range. But proof is in the pudding..let's see if it will continue this range in the future.

squirtthecat · October 12, 2009, 02:41:13 PM

Quote from: JDNC on October 12, 2009, 02:32:10 PM
Squirtthecat,

Yep, all three pads and out the top! Based on what I've read..some report that they can't tell much difference after the mod, but most do. I really didn't think I would see much myself (but what the heck) and was very much pleased to find 4 times the range. But proof is in the pudding..let's see if it will continue this range in the future.

10-4!
I'll see if I can find my soldering pen, and enough chutzpah to actually try it.

Or maybe pop in in the mail to you, with a Jackson, and ask you to do it... ;)

JDNC · October 12, 2009, 03:22:38 PM

I'm sure you can do it..I've been thinking that you might could use small brass tubing 1/8" or less for the antenna. Epoxy it into the case and solder to it connected it to the board with a small wire. I just happened to have the small stainless remote antenna on hand..but they're hard to come by unless you have one. The only problem with the small brass tube is that it would be easy to damage. But if you could find one that would slide in the other you could epoxy a 1/4" of the larger into the case crimping the bottom (the end to solder the wire to) creating a stop for the smaller tube (antenna). That way you could pull the antenna out for storage. I've found the brass tubing in hobby shops in the past in 10-12" sections. For that matter you could use a small section of tubing in the case and use solid copper or brazing rod for the antenna.

squirtthecat · October 12, 2009, 03:27:31 PM

Quote from: JDNC on October 12, 2009, 03:22:38 PM
I'm sure you can do it..I've been thinking that you might could use small brass tubing 1/8" or less for the antenna. Epoxy it into the case and solder to it connected it to the board with a small wire. I just happened to have the small stainless remote antenna on hand..but they're hard to come by unless you have one. The only problem with the small brass tube is that it would be easy to damage. But if you could find one that would slide in the other you could epoxy a 1/4" of the larger into the case crimping the bottom (the end to solder the wire to) creating a stop for the smaller tube (antenna). That way you could pull the antenna out for storage. I've found the brass tubing in hobby shops in the past in 10-12" sections. For that matter you could use a small section of tubing in the case and use solid copper or brazing rod for the antenna.

Thanks JD. I'll give it a shot!