Home |
Search |
Today's Posts |
#12
![]() |
|||
|
|||
![]()
Richard,
I believe the K2 is what you should be aiming to compete with. It evidently is fairly good for the money. I'm in Melbourne and would be happy to help in any way I can, time allowing. All the best, Rob Richard Hosking wrote: Rob My long term goal is to design a backback portable HF SSB/data rig to compete with the current offerings (SG2020) and Elecraft. I will probably never get there! I think with some new ideas and SM technology I could get the current drain 100mA on receive and keep the size V small, while having digital programmability etc BTW I would be interested in formiong a cooperative group on this if anyone is interested. Richard Rob Judd wrote in message ... Richard, How extremely strange. I just announced a week or so ago on a private forum that I was designing exactly the same thing. And I've also searched the net to see whether this was an original idea, and it seemed to be unique at the time. You wouldn't be another SDR-1000 owner by any chance? BTW, I'm still trying to locate relays also. My reply at the quoted $10.00 price from CIT was "Freow! Skip it!" or something similar. As you say, 20-30 of those makes it VERY expensive indeed. Rob Richard Hosking wrote: Anyone know a good source of surface mount latching relays DPST or DPDT, 5V to be driven by logic? I want to build an automatic antenna tuner for HF QRP Digikey has them but they areUS$12 ea and it is a bit too expensive if I want about 20 of them I would prefer a permanent source if possible - not only a temporary surplus - although this would be better than nothing Thanks in advance Richard |
#13
![]() |
|||
|
|||
![]()
Richard,
I believe the K2 is what you should be aiming to compete with. It evidently is fairly good for the money. I'm in Melbourne and would be happy to help in any way I can, time allowing. All the best, Rob Richard Hosking wrote: Rob My long term goal is to design a backback portable HF SSB/data rig to compete with the current offerings (SG2020) and Elecraft. I will probably never get there! I think with some new ideas and SM technology I could get the current drain 100mA on receive and keep the size V small, while having digital programmability etc BTW I would be interested in formiong a cooperative group on this if anyone is interested. Richard Rob Judd wrote in message ... Richard, How extremely strange. I just announced a week or so ago on a private forum that I was designing exactly the same thing. And I've also searched the net to see whether this was an original idea, and it seemed to be unique at the time. You wouldn't be another SDR-1000 owner by any chance? BTW, I'm still trying to locate relays also. My reply at the quoted $10.00 price from CIT was "Freow! Skip it!" or something similar. As you say, 20-30 of those makes it VERY expensive indeed. Rob Richard Hosking wrote: Anyone know a good source of surface mount latching relays DPST or DPDT, 5V to be driven by logic? I want to build an automatic antenna tuner for HF QRP Digikey has them but they areUS$12 ea and it is a bit too expensive if I want about 20 of them I would prefer a permanent source if possible - not only a temporary surplus - although this would be better than nothing Thanks in advance Richard |
#14
![]() |
|||
|
|||
![]()
Rob
A quick search of the revealed not much apart from the two mentioned. I have not used either but on paper at least, the 2020 appeared the most attractive. Elecraft kindly published their tuner design, which is simply a series of capacitors and inductors in a L network configuration switched by relays. They use a conventional SWR bridge to measure the match, with the whole thing controlled by a micro. Is that how you are planning to do yours? I have done a few successful projects using AVRs to control RF devices (see http://members.iinet.net.au/~richardh/VK6BRO.htm ) so I reckon I could do the board design. The code would take a bit of work - I am not sure what algorithm would be used Do you have any ideas on this? Richard Rob Judd wrote in message ... Richard, I believe the K2 is what you should be aiming to compete with. It evidently is fairly good for the money. I'm in Melbourne and would be happy to help in any way I can, time allowing. All the best, Rob Richard Hosking wrote: Rob My long term goal is to design a backback portable HF SSB/data rig to compete with the current offerings (SG2020) and Elecraft. I will probably never get there! I think with some new ideas and SM technology I could get the current drain 100mA on receive and keep the size V small, while having digital programmability etc BTW I would be interested in formiong a cooperative group on this if anyone is interested. Richard Rob Judd wrote in message ... Richard, How extremely strange. I just announced a week or so ago on a private forum that I was designing exactly the same thing. And I've also searched the net to see whether this was an original idea, and it seemed to be unique at the time. You wouldn't be another SDR-1000 owner by any chance? BTW, I'm still trying to locate relays also. My reply at the quoted $10.00 price from CIT was "Freow! Skip it!" or something similar. As you say, 20-30 of those makes it VERY expensive indeed. Rob Richard Hosking wrote: Anyone know a good source of surface mount latching relays DPST or DPDT, 5V to be driven by logic? I want to build an automatic antenna tuner for HF QRP Digikey has them but they areUS$12 ea and it is a bit too expensive if I want about 20 of them I would prefer a permanent source if possible - not only a temporary surplus - although this would be better than nothing Thanks in advance Richard |
#15
![]() |
|||
|
|||
![]()
Rob
A quick search of the revealed not much apart from the two mentioned. I have not used either but on paper at least, the 2020 appeared the most attractive. Elecraft kindly published their tuner design, which is simply a series of capacitors and inductors in a L network configuration switched by relays. They use a conventional SWR bridge to measure the match, with the whole thing controlled by a micro. Is that how you are planning to do yours? I have done a few successful projects using AVRs to control RF devices (see http://members.iinet.net.au/~richardh/VK6BRO.htm ) so I reckon I could do the board design. The code would take a bit of work - I am not sure what algorithm would be used Do you have any ideas on this? Richard Rob Judd wrote in message ... Richard, I believe the K2 is what you should be aiming to compete with. It evidently is fairly good for the money. I'm in Melbourne and would be happy to help in any way I can, time allowing. All the best, Rob Richard Hosking wrote: Rob My long term goal is to design a backback portable HF SSB/data rig to compete with the current offerings (SG2020) and Elecraft. I will probably never get there! I think with some new ideas and SM technology I could get the current drain 100mA on receive and keep the size V small, while having digital programmability etc BTW I would be interested in formiong a cooperative group on this if anyone is interested. Richard Rob Judd wrote in message ... Richard, How extremely strange. I just announced a week or so ago on a private forum that I was designing exactly the same thing. And I've also searched the net to see whether this was an original idea, and it seemed to be unique at the time. You wouldn't be another SDR-1000 owner by any chance? BTW, I'm still trying to locate relays also. My reply at the quoted $10.00 price from CIT was "Freow! Skip it!" or something similar. As you say, 20-30 of those makes it VERY expensive indeed. Rob Richard Hosking wrote: Anyone know a good source of surface mount latching relays DPST or DPDT, 5V to be driven by logic? I want to build an automatic antenna tuner for HF QRP Digikey has them but they areUS$12 ea and it is a bit too expensive if I want about 20 of them I would prefer a permanent source if possible - not only a temporary surplus - although this would be better than nothing Thanks in advance Richard |
#16
![]() |
|||
|
|||
![]()
On Sun, 7 Sep 2003 17:31:00 +0800, "Richard Hosking"
wrote: Anyone know a good source of surface mount latching relays DPST or DPDT, 5V to be driven by logic? Anyone have a URL on to how to use latching relays ?. I've found single coil and double coil examples but no info on how they function or how to switch them. |
#17
![]() |
|||
|
|||
![]()
On Sun, 7 Sep 2003 17:31:00 +0800, "Richard Hosking"
wrote: Anyone know a good source of surface mount latching relays DPST or DPDT, 5V to be driven by logic? Anyone have a URL on to how to use latching relays ?. I've found single coil and double coil examples but no info on how they function or how to switch them. |
#18
![]() |
|||
|
|||
![]()
The latching relays are fairly obvious, actually.
For the dual coil ones, you apply current to one coil to open, to the other coil to close. The single coil ones generally have you reverse polarity on the coil to change state. If they are latching relays, in both cases they won't change state with no current applied. ... "Mike W" wrote in message ... On Sun, 7 Sep 2003 17:31:00 +0800, "Richard Hosking" wrote: Anyone know a good source of surface mount latching relays DPST or DPDT, 5V to be driven by logic? Anyone have a URL on to how to use latching relays ?. I've found single coil and double coil examples but no info on how they function or how to switch them. |
#19
![]() |
|||
|
|||
![]()
The latching relays are fairly obvious, actually.
For the dual coil ones, you apply current to one coil to open, to the other coil to close. The single coil ones generally have you reverse polarity on the coil to change state. If they are latching relays, in both cases they won't change state with no current applied. ... "Mike W" wrote in message ... On Sun, 7 Sep 2003 17:31:00 +0800, "Richard Hosking" wrote: Anyone know a good source of surface mount latching relays DPST or DPDT, 5V to be driven by logic? Anyone have a URL on to how to use latching relays ?. I've found single coil and double coil examples but no info on how they function or how to switch them. |
#20
![]() |
|||
|
|||
![]()
Thanks
I wanted to know this as well! Richard xpyttl wrote in message ... The latching relays are fairly obvious, actually. For the dual coil ones, you apply current to one coil to open, to the other coil to close. The single coil ones generally have you reverse polarity on the coil to change state. If they are latching relays, in both cases they won't change state with no current applied. .. "Mike W" wrote in message ... On Sun, 7 Sep 2003 17:31:00 +0800, "Richard Hosking" wrote: Anyone know a good source of surface mount latching relays DPST or DPDT, 5V to be driven by logic? Anyone have a URL on to how to use latching relays ?. I've found single coil and double coil examples but no info on how they function or how to switch them. |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
Additional Line Losses Due to SWR | Antenna | |||
Subject: IC-2AT and 12 Volt Power Source | Equipment | |||
Tx Source Impedance & Load Reflections | Antenna | |||
Is it possible to have a 1:1 SWR? | Antenna | |||
A Subtle Detail of Reflection Coefficients (but important to know) | Antenna |