Glad to see you solved the problem and that I could be a part of it.
Hello to all.
I have just testet one board - transmission / amplification. Since I don’t have any rf power measurement equipment I can only say that there is a SIGNIFICANT difference in range when enabling MAX2430 amplifier that’s on board.
I am receiving audio-transmission of signal on MVT7100 receiver scanner, so no data-transfer has been tested yet.
The basic idea works, rf switches work, max2430 amplifies the signal (still don’t know how much). The only thing I havent tested yet is the sensitivity of receiver because the signal is passing through two RF switches on it’s way to the CC1101 modem. There might be some loss but not much I hope :roll:
I just wish I have thought of using rf baluns from a GSM phone instead of all those passive components on the RF front end of CC1101.
Regards,
Muris
I just saw something interesting in the following ti doc:
http://focus.tij.co.jp/jp/lit/an/swra168a/swra168a.pdf
Your amp has plenty of gain, but his might help improve sensitivity if you have a problem.
All CC11xx chips are characterized on a reference design using multilayer type SMD
inductors. These reference designs can be downloaded from http://www.ti.com/lpw and
contains description of component types and values. Approximately 2 dB higher output power
and reduction of harmonic emission, above 5 GHz, with more than 10 dB can be achieved by
replacing the Multi Layer (ML) type inductors with Wire Wound (WW) inductors. The tradeoff
is that WW inductors are more expensive than ML. See section 5 for more information about
how the inductor type affects the performance.
Thanks for the info, I will take a look. 8)
Hello,
I am giving away few of my PCBs so if someone would like them, please contact me on PM.
Images:
Regards!](http://www.elektronika.ba/cc1101_c.jpg)](http://www.elektronika.ba/cc1101_b.jpg)](http://www.elektronika.ba/cc1101_a.jpg)
I’m a little tempted to say that I want some, but I don’t have time to use them. It would also distract from my long term plan of designing enough boards to order a panel from gold phoenix 
Muris:
Hello,I am giving away few of my PCBs so if someone would like them, please contact me on PM.
Images:
Regards![/quote]
how did you solder the chips and SMDs?](http://www.elektronika.ba/cc1101_c.jpg)](http://www.elektronika.ba/cc1101_b.jpg)](http://www.elektronika.ba/cc1101_a.jpg)
stevech:
how did you solder the chips and SMDs?
I dont know how he did.
But I have done similar things (ATMEGA88) like this:
A tiny drop of solder cream on each surface.
Place the components.
Kitchen stove at 250 degrees celcius.
Put PCB in oven for 2 minutes.
All 3 boards I have made this way have worked.
Perhaps its possible to do this with a shorter time in the oven.
I have not tested out what the optimal temp and time is yet. Anybody who knows this?
/Henrik
PS
Oh I forgot to say I friend who is a hardware designer, said that it would not work to do it in a kitchen stove. I tried it anyway.
PS2
I too wish to use the CC1101. I have found a company called shortlink that make small daugther boards with the all RF already done which I then hand solder onto my PCB, I did not put those in the oven. I am about to do the SW now…
Hello,
I don’t know why I didn’t get an E-mail notification about posts in this topic, but never mind.
I soldered them with [NET 850, smd rework station (made in China) 
Did the same preparation as xehpuk but instead of cooking it in the oven, I used this NET 850 “rework” station to cook it with hot air.
Anyway, yesterday I ordered boards from Batch PCB for a new improved version. This new version has on-board level converter 5V<->3.3V and it accepts inputs of 5V. I also used all chips from Maxim-IC this time, except for CC1101 which is from TI and HMC RF switch which is from Hittite.
This time, the output power is 250mW because Maxim-IC stopped manufacturing the MAX2430 (125mW) which was used on the previous board. I didn’t like the previous board because I really wish that I had onboard level converter, but now I will 
P.S. I am still giving away these boards with MAX2430 so if anybody is interested, let me know.
P.S.2. I also need 5 pcs of SN74LVC1G04 (SOT-23-5) for testing my new boards and I can’t order them from anywhere because nobody offers cheap delivery methods, they all deliver with Fedex or UPS. So, if somebody can sell me these 5 chips it would be great. Thanks in advance!
Regards!](http://www.meyear.com/images/850.jpg)
Hello,
Here it is:
http://www.elektronika.ba/P9020136.JPG
It is CC1101 with 250mW power amplifier. Works great, testing is still in progress. I achieved 1026 meters of range with no line-of-sight. The signal went from [here to [here.](Google Maps)](Google Maps)
Muris:
Hello,Here it is:
http://www.elektronika.ba/P9020136.JPG
It is CC1101 with 250mW power amplifier. Works great, testing is still in progress. I achieved 1.026 meters of range with no line-of-sight. The signal went from [here to [here.[/quote]
I hope you meant 1 km
Or you forgot to attach the antenna :)](Google Maps)](Google Maps)
:lol: yes, 1 km.
It goes even 400m without an antenna on the receiver, no line-of-sight! I didn’t fully test the range yet.
I realized my mistake, damn differences between the use of “.” and “,” for decimal representation
Work voltage of module is 1.8V-3.6V, recommending to use 2.8V. If the working voltage of MCU is higher than module`s, between each working port and MCU I/O port must be linked with resistance in series to separate them, and the range of supplying voltage between them is not too far. (recommending the same power supply to offer electricity)
Muris:
:lol: yes, 1 km.It goes even 400m without an antenna on the receiver, no line-of-sight! I didn’t fully test the range yet.
Congratulations on getting it working! What were the conditions? Hilltop to Hilltop?
I have done quite a bit of 902-928Mhz spread spectrum design work. I can give you a couple of hints that might help dramatically increase your range. You should be able to achieve 20km or more from hilltop to hilltop easily even with 6 inch 2dB halfwave dipole antennas. If you are using FR4 pcb material, then make sure you are using 0.031" material. It looks like you are using 0.062 material from the images. Also (assuming .031" FR4), make your 50 ohm traces 55 mils wide. Note that you have to have a good ground plane underneath the microstrip trace to form a 50 ohm transmission line.
There are microstrip calculator around on the net:
http://www1.sphere.ne.jp/i-lab/ilab/tool/ms_line_e.htm
Try
Er 4.7 (dielectric constant for FR4)
Height 0.031 inches
Freq: 915mhz
Zo (characteristic impedance) 50 ohms
Will result in trace width of app. 55 mils
If you are using 0.062" FR4, the traces would have to be 110 mils. That just isn’t very feasible for the small parts that we are working with.
0.031" material just seems to work much better though. There are other pcb materials that allow thinner traces due to different dielectric, but they get expensive.
Here is the whole project: http://www.elektronika.ba/629/cc1101-rf … amplifier/
Muris:
Here is the whole project: http://www.elektronika.ba/629/cc1101-rf … amplifier/
Here is another project using the CC1101 that I have been working on for some time. It is a 50 channel frequency hopper with 15.5 millisecond dwell time. The RF output power is 28.3 dBm. You might find it interesting. I recently did a range test and easily achieved 19.5 kilometers with 6 inch, 2.1 dB antennas and only 3 meters above the surface. Test packets were 64 bytes, bi-directional.
range test:
Hey this looks really impressive. This is on 433 MHz?
Muris:
Hey this looks really impressive. This is on 433 MHz?
No, it is 902-928 Mhz 50 channels, so very similar to the 868Mhz European freqeuncy. In the U.S this is one of the ISM band (industrial, scientific, medical) and allows for license free use (still requires certification). You can transmit up to 1 Watt conducted if you meet certain requirements like 50 channels, pseudo-random hop pattern, etc.
I only mentioned the link because you asked for advice at the beginning of the thread. I had also mentioned in my November post that 20Km was achievable with 6 inch whip antennas, so I figured I better do more than talk
The CC1101 is one impressive little part.
Cheers,
tve
Hello everybody,
I would like to build some of this nice transceivers. But I can’t find the MAX 2233 to buy. Cause I wana build about 10 to 15 (or more)MAXIM would not give me enough samples. 
So dose anyone know where to buy? (best in EU cause I’m form Germany)
Or a simular chip. I like the option of gain control.
Thanks a lot!
And once again GRAET WORK!!!