Post by thread:OT: Looking for small 2.4 GHz TX RX pair

Hi ,I'm looking for a small 2.4 GHz TX - RX pair for a PIC based project I'm working on. The RX should be small enough to strap onto a PDA without it becoming to obtrusive. The data link only has to be one way. Does anyone know of anything I should look at? Thanks! Jim

> Hi ,I'm looking for a small 2.4 GHz TX - RX pair for a PIC based project > I'm working on. If it has to be 2.4 GHz for world-wide use, you could try Digital Wireless. Sorry I don't have the URL. I've been testing them, they only sort of work, but it might still be me... If you can go to 900 MHz (US only), try the modules from Linx. http://www.linxtechnologies.com Cheaper, Simpler, seem to work. Regards, Barry. ------------ Barry King, KA1NLH Engineering Manager NRG Systems "Measuring the Wind's Energy" Hinesburg, Vermont, USA spam_OUTbarryTakeThisOuTnrgsystems.com "The witty saying has been deleted due to limited EPROM space"

Check out RFM. They may have a 2.4 GHz solution by now. Their TR series hybrid transceivers are pretty awesome even at $12 CAN each (low vol), and they can support data rates 2x that of the linx modules. The linx modules cost us $50 CAN each for just the transmitter or the receiver and they insisted that we purchase the development kit for a few hundred before we were allowed to purchase the modules. Not so with RFM, and I can purchase them from the local Insight rep, instead of through the painfully slow US/CAN customs route. The RFM transceivers are .28 x .40 x 0.08 inches. The linx modules are significantly larger at 1.3 x 1.1 x 0.2 inches for the transmitter and 2 x 1.2 x 0.5 inches for the receiver. The only advantage I see that the Linx modules have over the RFM units is that Linx can transmit audio just as well as data and it can be digitally tuned on the fly to one of 8 channels. The RFM modules use fixed saw technology thus only fixed freq. are available. Craig > {Original Message removed}

Hi, If you do get the RFM product to work please email me I have hundreds of there ASH receivers and Transmitters THAT DONT WORK. Julian Fine .....julianKILLspam@spam@fine.co.za Eagle Wireless Security http://www.fine.co.za Tel +2712 664 6688 Fax +2712 664 0857 Mobile 082 492 5294 or SMS 083 288 2807 {Original Message removed}

Jim Ruxton wrote: > Hi ,I'm looking for a small 2.4 GHz TX - RX pair for a PIC based > project I'm working on. The RX should be small enough to strap onto a > PDA without it becoming to obtrusive. I think you've got a conceptual problem here. (Low-power) 2.4 GHz equipment is portable, not mobile. It works by sitting the unit on some furniture and aiming receiver at transmitter and vice versa. You may not have to aim too accurately, but it is not the sort of thing you walk around with. Even less so if it's one-way because you depend on acknowledgements and retransmission ("packet" protocols) to get the data through if the link is anything other than fixed. -- Cheers, Paul B.

In a message dated 7/14/99 7:50:02 AM Eastern Daylight Time, paulbKILLspamMIDCOAST.COM.AU writes: > Jim Ruxton wrote: > > > Hi ,I'm looking for a small 2.4 GHz TX - RX pair for a PIC based > > project I'm working on. The RX should be small enough to strap onto a > > PDA without it becoming to obtrusive. > > I think you've got a conceptual problem here. (Low-power) 2.4 GHz > equipment is portable, not mobile. It works by sitting the unit on some > furniture and aiming receiver at transmitter and vice versa. > > You may not have to aim too accurately, but it is not the sort of > thing you walk around with. Even less so if it's one-way because you > depend on acknowledgements and retransmission ("packet" protocols) to > get the data through if the link is anything other than fixed. > -- > Cheers, > Paul B. > How do the newer 2.4GHz cordless phones work then?! Do you have to talk in the same room as the reciever and stand in a certain posistion? I think not. Matt

I am not sure what you are looking for, but I had some wireless video projects where I needed some small transmitters and cool stuff like that. I _finally_ found somewhere to buy that stuff, http://www.mscelectronics.com the guy there was very knowedgable, and got me pointed in the right direction. they have some really good quality 2.4gig fm video stuff, and about a month of my paychecks :) ---Lou {Original Message removed}

> Jim Ruxton wrote: > > > Hi ,I'm looking for a small 2.4 GHz TX - RX pair for a PIC based > > project I'm working on. The RX should be small enough to strap onto a > > PDA without it becoming to obtrusive. > > I think you've got a conceptual problem here. (Low-power) 2.4 GHz > equipment is portable, not mobile. It works by sitting the unit on some > furniture and aiming receiver at transmitter and vice versa. > > You may not have to aim too accurately, but it is not the sort of > thing you walk around with. Even less so if it's one-way because you > depend on acknowledgements and retransmission ("packet" protocols) to > get the data through if the link is anything other than fixed. > -- > Cheers, > Paul B. We manufacture a 2.4 GHz spread spectrum modem designed to sit on moving vehicles (AGV's). The range is about 500-1000 feet indoors, 3500 feet outdoors (20 miles with high gain directional antennas). It's a full duplex device. With automatic error checking and retransmitting on faults. Up to 115kbps. It uses an OEM module from Digital Wireless, check it out at http://www.digital-wireless.com/witb.htm ============================== Ruben Jvnsson AB Liros Elektronik Box 9124, 200 39 Malmv, Sweden TEL INT +4640142078 FAX INT +4640947388 .....rubenKILLspam.....2.sbbs.se ==============================

This question takes this discussion even more off topic. I just acquired a 2.4GHz phone system. I works really well, except when I need to go trough a concrete wall! I was wondering if anyone can suggest specs for an antenna that I can mount on the other side of the wall to get back the range that I have become accustom to? Also, is it possible to attach this external antenna onto the existing one in the base or will I have to crack open the case to attach it to the PCB directly? I know nothing about RF and need as much info as I can get. Thanks. David B. >>That's the difference between the aerials .I.e. Directional (Horn or dish >>etc) or omnidirectional (Dipole). >>The aerial depends on the amount of gain needed to cover the distances you >>require with the power available.

David Blain wrote: > I just acquired a 2.4GHz phone system. I works really well, except > when I need to go trough a concrete wall! That's the point I was making in my previous post. You can have small and cheap and one-way. You can have mobile operation. You can have reliable data transmission. You can have long range. However... When you want any TWO of these, you are in big trouble. If you think you want *three*, you are really pushing doo-doo up an incline. > I was wondering if anyone can suggest specs for an antenna that I can > mount on the other side of the wall to get back the range that I have > become accustomed to? That's the other thing. At this frequency, do-it-yourself RF design becomes *much* more difficult, compared even to VHF or UHF. *If* you have the resources of course, you can do great things, such as using flat PCB antennae instead of the horns and dipoles. -- Cheers, Paul B.

> > I was wondering if anyone can suggest specs for an antenna that I can > > mount on the other side of the wall to get back the range that I have > > become accustomed to? > > That's the other thing. At this frequency, do-it-yourself RF design > becomes *much* more difficult, compared even to VHF or UHF. *If* you > have the resources of course, you can do great things, such as using > flat PCB antennae instead of the horns and dipoles. Not suitable for the other side of a wall, but Digikey now carries a 2.4 GHz patch antenna.

I have three of the Hummingbird spread spectrum modems from Xetron that have been going non stop now for about 2 years with no problems. The evaluation kits that came with enclosures were $800 each. Craig Lee wrote: {Quote hidden}> Check out RFM. They may have a 2.4 GHz solution by now. > > Their TR series hybrid transceivers are pretty awesome even at $12 CAN each > (low vol), > and they can support data rates 2x that of the linx modules. > > The linx modules cost us $50 CAN each for just the transmitter or the > receiver > and they insisted that we purchase the development kit for a few hundred > before > we were allowed to purchase the modules. Not so with RFM, and I can > purchase them > from the local Insight rep, instead of through the painfully slow US/CAN > customs route. > > The RFM transceivers are .28 x .40 x 0.08 inches. The linx modules are > significantly > larger at 1.3 x 1.1 x 0.2 inches for the transmitter and 2 x 1.2 x 0.5 > inches for the > receiver. > > The only advantage I see that the Linx modules have over the RFM units is > that Linx > can transmit audio just as well as data and it can be digitally tuned on the > fly to > one of 8 channels. The RFM modules use fixed saw technology thus only fixed > freq. > are available. > > Craig > > > {Original Message removed}