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[dhouston]

I have an existing preamplified eggbeater antenna design (plus an inventory of preamps and other components) which I'll be using with my RR5x5 project.

It would be a simple matter to design a 50-ohm BNC connector with a small attached PCB to supply power from a CM15A to the preamp over the coax.

I have someone lined up to build/distribute kits that would include a preassembled antenna base w/preamp, 6'3" of coiled, precut copper-clad wire with two pieces of 36" heat-shrink already on it and the two ends preformed. Users would need to cut the antenna wire at the mid-point, form the resulting ends and attach the loops to the base. They would also need to modify the CM15A case to mount the BNC connector and solder three leads (5V, Vss, RCVR). I will provide photos of the CM15A modifications. The individual providing the kits will also have pre-made 50-ohm coax in 1' to 50' lengths. My preliminary guesstimate is that it will cost about $35 plus any coax plus Priority Mail. It will probably take 6 weeks or so to get things rolling should there be enough interest to justify buying PCBs, etc.

You can see the eggbeater antenna details at http://davehouston.org/eggbeater.pdf

[Knightrider]

I think I might be game to try one.

[bvrwally]

I too may be interested Dave! Sounds like a good plan!!

[Andytec]

Just wanted to let you know I made one yesterday and it works great - cost me about $6 tops
Thanks for the idea

Andy

[dhouston]

... cost me about $6 tops

The $35 guesstimate includes copper-clad steel wire pre-cut and with ends pre-formed, heat-shrink tubing to insulate it, the enclosure w/preamp, phasing line and all the nuts & bolts pre-installed as well as the BNC connector with PCB to pass 5V up the coax from the CM15A.

[m82a1pa]

I'd really be interested in getting a kit.  Thanks.

[Marcio Ylasova]

Just wanted to let you know I made one yesterday and it works great - cost me about $6 tops
Thanks for the idea

Andy

WOW! $6? maybe you found a good store that sells ingredient for the egg beater antenna @ very affordable price. And I found also a site that sells heat shrink tubes at low cost and high quality. Maybe you should check this http://www.cabletiesandmore.com/heatshrink.php to compare the prices and quality.

[luke03]

Great idea, Dave!

[mike]

... cost me about $6 tops

The $35 guesstimate includes copper-clad steel wire pre-cut and with ends pre-formed, heat-shrink tubing to insulate it, the enclosure w/preamp, phasing line and all the nuts & bolts pre-installed as well as the BNC connector with PCB to pass 5V up the coax from the CM15A.

Dave, r u plowing ahead with this?  Now that Mercury stopped being renigade, my SC1200 is again working (coincidence) ha!  but it is still marginal on receive strength of ds10s.  If u r going to do this please let us know asap.  Or i will be buying a tv antenna preamp like this and trying it:

http://www.google.com/products/catalog?q=rf+preamp+kit&um=1&ie=UTF-8&tbm=shop&cid=7703557689243124224&sa=X&ei=xOrvTrWAKcy1twew2-zgAw&ved=0CIoBEPMCMAI

or ramsey kit:

http://www.ebay.com/itm/Ramsey-SA7-Broadband-RF-Preamp-Kit-/360283781260?pt=LH_DefaultDomain_0&hash=item53e296388c#ht_1624wt_667

thanks.

[dhouston]

Yes, but it will be mid to late January before I have the printed circuit boards for providing power over the coax and before the person who will sell them ca get setup to take orders. Right now, I'm dealing with 15 different prototypes for my Zarduino^TM project.

If you don't want to wait, the Ramsey kit will work fine, especially if you build an eggbeater. I built and tested one a few years back. You will need a separate power supply for it.

The TenTec 1001 kit will also do a good job and also needs a separate power supply.

• http://www.tentec.com/products/Universal-Low%252dNoise-Broadband-DC-to-1-GHz-RF-Preamp.html

I don't recommend UHF/VHF preamps as they will have 75 ohm impedance while the eggbeater and the RF receiver are 50 ohms. The mismatches will cause losses. This is not a fatal flaw but I believe you should do it right.

[mike]

I'm really really good at procrastinating so mid jan is no prob  :...)

I'm lazy too so would prefer ur stuff to doing myself too.  

If I did my own I would prob not use the ramsey kit tho - its 4db noise is pretty hi and most tv cheap preamps are about 1/2 that I think.  also, I would have to modify the 9-12v supply input bias resistors and all to run off the lower sc12 voltage rather than needing a sep one...

Lastly, I give:  what is a zuichini(tm) all I can find on line is Arduino minus the trademark (open source)....

[dhouston]

Zarduino^TM

• http://davehouston.org/Zarduino.htm

although zucchini, sauteed in olive oil and dusted with freshly ground white pepper is excellent, too.  

[dhouston]

It apears that Mini-Circuits has discontinued the small preamp IC that I use for this so once my inventory plus that of the only other supplier I can find is gone (mine+his<100), we'll have to find another solution. 

[dhouston]

Dave, r u plowing ahead with this?  Now that Mercury stopped being renigade, my SC1200 is again working (coincidence) ha!  but it is still marginal on receive strength of ds10s.  If u r going to do this please let us know asap.  Or i will be buying a tv antenna preamp like this and trying it:

Mike,

I hadn't noticed that you want to use this with the SC1200. I've never seen the SC1200 and have no idea whether it's internal OEM antenna is isolated from the powerline. Any X10 device that can send PLC codes is suspect and one with an internal antenna is doubly suspect.  I cannot recommend adding an external antenna, whether with or without a preamp, without seeing a schematic of the SC1200.

Is there an FCC ID on the case? If so, I might find a schematic in the FCC filing. However, if they are using a superheterodyne receiver like in the CM15A, there is no longer a requirement for testing in an FCC-approved lab and, thus, there may be no FCC ID. (The CM15A also has an RF transmitter so it still requires testing and an FCC ID.)

[mike]

Little rcvr is very similar if not same as cm15 in looks;  I didnt copy chip no down and check it...  sc12 uses wall wart with like 9vdc output so I am pretty sure it is isolated but they may feed line thru a cap anyway; i will verify tomorrow when i go back out to shop.  i had sent u a pm today since I will have a couple tentec 1001 amps in a couple days so right now just would like to try eggbeater rather than my normal coaxial 14 wave.