Author Topic: WMR200 External Antenna (Read 18557 times)

gadget_guy · « **on:** October 17, 2010, 01:31:20 PM »

I had so much success adding an external antenna to my WMR100, I decided to do the same to my WMR200. Turns out it was even easier to modify the WMR200. The first step is to pry the black bezel off. It is just held in place with some sticky adhesive. Once that comes off, you will see five screws that hold the top and bottom together. See the first picture. Once you remove the screws, you can separate the top and bottom. In picture #2 you can see the daughter board where the antenna is connected. It turns out that the antenna is a dipole. The part outside the case is half of the dipole. The other half is bent around the edge of the bottom. I unsoldered and removed the old antenna and installed a SMA female connector. The hole in the case was a good fit for the connector. See photo 3. That's all it took. Now I can hook up the external antenna of choice. For now I made up a dipole from a couple of pieces of brass rod mounted on plexiglass. I'm using RG174 coax with a SMA Male connector to connect the antenna to the WMR200. Makes a tremendous difference. It was well worth the effort.

stevebrtx · « **Reply #1 on:** October 17, 2010, 04:37:57 PM »

No we're talking, my 100 has never had a problem, the 200 is nothing but a problem. As soon as I get back from a trip north of the border I'll give it a try, thanks for the investigation and solution to a factory problem.

gadget_guy · « **Reply #2 on:** October 17, 2010, 05:21:29 PM »

It's funny but for me the WMR200 has far better reception than the WMR100. Luck of the draw I guess. In any event both consoles work much better with an external antenna.

killwilly · « **Reply #3 on:** October 18, 2010, 02:01:07 AM »

Quote from: gadget_guy on October 17, 2010, 05:21:29 PM

It's funny but for me the WMR200 has far better reception than the WMR100. Luck of the draw I guess. In any event both consoles work much better with an external antenna.

With me it is the reverse. However, a quick fix for the 200 is to wrap copper wire around the antenna and extend it upwards for about 12 inches, not pretty, but it does the job fine.

Alan

gadget_guy · « **Reply #4 on:** October 18, 2010, 09:59:48 AM »

A passively coupled antenna is certainly better than nothing. However an antenna tuned to the proper frequency is always the best. Adding an external jack also lets you choose the antenna design. In extreme cases you could also build a directional antenna such as a Yagi. Alas my sensors are not all located in the same direction from the console so an omni directional antenna was necessary. I may even move the antenna to the outside at one station since the console is in the basement. I'll see how things are working in a couple of weeks.

jonkjon · « **Reply #5 on:** December 28, 2010, 10:30:13 PM »

Thanks for the pics on getting to the antenna. Would it be possible for you to supply links to the parts? i.e, the sma connector you soldered in and also the antenna? Thanks again for the excellent write up!

gadget_guy · « **Reply #6 on:** December 29, 2010, 09:51:27 AM »

I got the coax and connectors on eBay. I'll try and find the listing. I bought from a dealer who has the stuff all the time. Glad you liked the writeup. I've had no issues since installation, and performance has really improved.

jonkjon · « **Reply #7 on:** December 29, 2010, 05:23:05 PM »

Thanks so much for the help......

Scalphunter · « **Reply #8 on:** December 29, 2010, 05:29:31 PM »

Bet the local Radio Shack dealer will have what you need as they as an common item.

gadget_guy · « **Reply #9 on:** December 29, 2010, 07:53:06 PM »

Here is a link to the dealer I bought the connectors and coax from. The female ends are real short. I cut off one end the U.FL male plug leaving the female SMA. I also bought the 30 ft of RG174 with a male SMA on each end. I cout that in half and made two antennas with that coax. The price was right and the local RS did not have what I needed. Furthermore, I did not have crimp tools for the SMA connectors.

http://shop.ebay.com/3n201/m.html

jonkjon · « **Reply #10 on:** December 29, 2010, 09:33:40 PM »

Quote

I cout that in half and made two antennas with that coax.

I'm with you on the sma connectors etc, but am curious what you mean by making two antennas out of the 30 ft. of coax. Forgive me for being so dense...

gadget_guy · « **Reply #11 on:** December 29, 2010, 10:07:08 PM »

I should have said feed lines for two antennas. I actually made the antennas out of brass rod. The coax was soldered to the rods that made the dipole. Since I had 30' of coax with a male connector at each end, I just cut the coax at the 15 foot mark and had the makings to feed two antennas and each feedline had the male connector on the console end.

jonkjon · « **Reply #12 on:** December 29, 2010, 11:02:54 PM »

Do you just solder the center wire from the coax to the brass rod? If I might also ask, what diameter and length were the brass rods?

gadget_guy · « **Reply #13 on:** December 30, 2010, 08:48:20 AM »

You will need two pieces of rod approximately 6.485 inches long. You will make an antenna that resembles the old TV rabbit ears. The center conductor of the coax goes to one rod the shield goes tot he other. I use a piece of plastic to mount the two sections in a straight line. I'll put up a photo later.

duke666 · « **Reply #14 on:** January 04, 2011, 01:27:34 PM »

Quote from: gadget_guy on December 30, 2010, 08:48:20 AM

You will need two pieces of rod approximately 6.485 inches long. You will make an antenna that resembles the old TV rabbit ears. The center conductor of the coax goes to one rod the shield goes tot he other. I use a piece of plastic to mount the two sections in a straight line. I'll put up a photo later.

Looking and getting a 200 myself and want to avoid the possible comms problems from the start. Any chance of that pic to be sure what to do?

Duke

gadget_guy · « **Reply #15 on:** January 04, 2011, 10:07:28 PM »

Yes. I was out of town for a few days, but I'll definately post one tomorrow.

gadget_guy · « **Reply #16 on:** January 06, 2011, 07:18:14 PM »

Here is the promised picture of the dipole external antenna I use for both the WMR100 and WMR200. You can see (I hope) that the shield of the coax is soldered to one of the brass rods, the center conductor is soldered to the other. There is nothing magical about using brass. Copper would be just as good. It's just that I had some brass rods lying around.

jonkjon · « **Reply #17 on:** January 06, 2011, 07:31:41 PM »

Thanks for taking the time to post this.....I have been reading quite a bit about antennas (and have ordered and received the parts from your link....thanks) and was wondering something. I thought that I read somewhere that with dipoles like this, it was best if the lead with the solid center strand was pointing upwards. Have you experimented or found something other than this to be the case?

duke666 · « **Reply #18 on:** January 08, 2011, 02:21:07 AM »

Thanks for the pic.

Duke

jonkjon · « **Reply #19 on:** January 08, 2011, 08:18:25 AM »

Got mine up and running yesterday. I wimped out and bought a 433mhz dipole from digi-key. I have the OS uv sensor and it still dropped out but it's not a very good device anyway. I'll wait and see how everything else does for a few days....
BTW, if you do this, be real careful with the bezel. I had mine about 3/4 of the way off and it cracked right as I was just about finished removing it. Oh well, if the antenna works, it's worth it!

Had another drop on the anemometer so I went ahead and built an antenna per your specs. I stripped out some copper wire and straightened it out in lieu of the brass rods. Soldered them in and put the antenna in the window. Right away, the uv sensor came back up. (The anemometer had already come back) I'll keep my fingers crossed!

stevebrtx · « **Reply #20 on:** January 08, 2011, 01:14:31 PM »

My 200 hangs on a wall, so I took a slightly different approach, finding an SMA connector, coax etc. in MX is a fools errand, so I clipped the antenna wire about one half inch from the board so I still had a lead to solder to, removed the antenna, drilled a hole in the bottom of the short section, threaded a small wire and soldered it to a piece of coat hanger wire, about half an inch from the end, slipped the soldered portion back up into the antenna and epoxied it in place, then reconnected the lead.

With the new "antenna" sticking out of the original, you can rotate it to position it pointing up, or down from the unit. I tried up, didn't work, so went to down and it's working great.

jonkjon · « **Reply #21 on:** January 09, 2011, 10:41:57 AM »

Quote from: stevebrtx on January 08, 2011, 01:14:31 PM

My 200 hangs on a wall, so I took a slightly different approach, finding an SMA connector, coax etc. in MX is a fools errand, so I clipped the antenna wire about one half inch from the board so I still had a lead to solder to, removed the antenna, drilled a hole in the bottom of the short section, threaded a small wire and soldered it to a piece of coat hanger wire, about half an inch from the end, slipped the soldered portion back up into the antenna and epoxied it in place, then reconnected the lead.

With the new "antenna" sticking out of the original, you can rotate it to position it pointing up, or down from the unit. I tried up, didn't work, so went to down and it's working great.

Can you post a pic? The antenna mod gadget_guy built isn't working too well for me. I am having a lot of drops today. So far it's recovering, but it seems to be dropping fairly frequently. I think I may look into shortening the length of coax to reduce the effects of impedance on any db gain. I'm also not sure of how high to mount it, how to orient it or if I should move it outside. If none of that works, i may just reinstall the original.

gadget_guy · « **Reply #22 on:** January 09, 2011, 09:13:10 PM »

Usually best results occur when really diving a d transmitting antennas are oriented in the same direction. I thinkall the sensors or at least most are oriented vertically

stevebrtx · « **Reply #23 on:** January 10, 2011, 10:08:07 AM »

Sorry, I didn't take any pics and it was totally unscientific, I just took the long straight section of a coat hanger without consideration as to frequency. So, all you see is all but about 1.5" of the rod sticking out of the short end of the antenna. So far it seems to be working ok, certainly an improvement over the original.

jonkjon · « **Reply #24 on:** January 11, 2011, 06:41:28 PM »

Quote from: jonkjon on January 08, 2011, 08:18:25 AM

Got mine up and running yesterday. I wimped out and bought a 433mhz dipole from digi-key. I have the OS uv sensor and it still dropped out but it's not a very good device anyway. I'll wait and see how everything else does for a few days....
BTW, if you do this, be real careful with the bezel. I had mine about 3/4 of the way off and it cracked right as I was just about finished removing it. Oh well, if the antenna works, it's worth it!

Had another drop on the anemometer so I went ahead and built an antenna per your specs. I stripped out some copper wire and straightened it out in lieu of the brass rods. Soldered them in and put the antenna in the window. Right away, the uv sensor came back up. (The anemometer had already come back) I'll keep my fingers crossed!

Update......

I was still having frequent drops with this so I went ahead and shortened the coax to a couple of feet. I also oriented the antenna vertically and moved it to a higher location and not in the window I had it in. I was thinking that maybe the screen in the window might be interfering with things. The copper lengths are also now completely unobstructed unlike they were when stuck between the window panes. So far today, no drops at all. I can tolerate the drops as long as the sensors return quickly when the console starts hunting for them. But, like I said, almost a full day with no drops at all. I'll post again with more results.......
Tonight we have a fair amount of icing so it's off to the rain gauge heater sticky in the forums!

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Author Topic: WMR200 External Antenna (Read 18557 times)