Did a decision of which relays are going to be used as the relay of choice for the largest number of people and that will fit the board without modifying it ? I have several SMD size Omrons on hand, but the particular ones that I have on hand are not a good choice, without doing some modifications that would deviate from the present scheme being used.
Also a recommended supplier for both models required would be appreciated. That is pretty much all that I am lacking, as best that I can tell, and would like to get the correct size and type on order before my boards arrive, so I can get started right away on the entire rig, but I will still build it a section at a time to share my build of it, with pictures and notes as I go along.
73, Charlie, W5COV On 3/17/2014 1:00 PM, Thomas Sarlandie wrote:
Jeremy,For the inductor in the BFO, yes you can use the same core and windings as for the other one. That is what I did.Even if you are using an external amplifier you will probably need some way to tell the amplifier which band you are transmitting on so it can turn on the proper LPF. I don't think there is a standard way to do this. The fanciest amp will automatically detect the frequency in the incoming signal, some will use proprietary connections, some will require the user to push buttons, etc.73, thomasOn Mon, Mar 17, 2014 at 7:10 AM, Jeremy Chase <jeremychase@xxxxxxxxx <mailto:jeremychase@xxxxxxxxx>> wrote:Thomas, Thank you very much! I've incorporated your answers and have 2 followup questions. They are inline: 1. Can the 3u inductor near T3 be the same type as the inductors in the filter? I guess you are referring to the inductor labelled "RFC" on Farhan's schematic. Farhan said: "The RFC is 10 turns on FT37-43" According to toroids.info <http://toroids.info>, that is 35 uH. I actually meant the inductor connectected to the 20Mhz crystal in in the BFO: https://www.dropbox.com/s/sa69fepffelwxfr/Screenshot%202014-03-17%2009.52.52.png 1. What is the 'BAND SELECT' part connected to PD6 and PD7 of the Arduino? This is a connector that would go to your power amplifier to switch different band-pass or low-pass filters depending on the band that you are on. The original idea was to use those 3 bits to select one band (3 bits = 8 possibilities). We have since then explored other options and Farhan has chosen the CD4017 option. Read "Bandswitching the low-pass filters" on the RF386 page for more info on the new design that will only take one line: http://www.hfsignals.org/index.php/RF386 So if the builder isn't planning to use an external amplifier they could omit this part. Is there a standard connector for BAND-SELECT chassis parts? 73 K2CHA
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