Hi Bruce MICRO1700.
For the first time in human history I disagree with something you said. You said that the Trisquare radios might be "off-subject," but I think it's totally on subject. Especially since you found there are audio inputs/outputs (for STL use?)
Find out if the specs mention the bandwidth, which would be a clue probably to the audio quality. My impression is that up in the 900mHz space, bandwidths are usually very generous.
Those spread spectrum 900 MHz radios sound interesting for this application. I don't know the governing rules but for the license free 400MHz FRS sets the transmissions have to automatically time out in about three minutes. If you drop the carrier periodically they reset and most two way users would not notice this. There is a lot of activity here on 400 MHz since it seems businesses use them and interference would be a problem.
Perhaps by using spread spectrum this timeout would not be required. Just something to check.
Neil
Those spread spectrum 900 MHz radios sound interesting for this application. I don't know the governing rules but for the license free 400MHz FRS sets the transmissions have to automatically time out in about three minutes. If you drop the carrier periodically they reset and most two way users would not notice this. There is a lot of activity here on 400 MHz since it seems businesses use them and interference would be a problem.
Perhaps by using spread spectrum this timeout would not be required. Just something to check.
Neil
An after thought that I forgot to post. I have read conflicting information about the current requirements of the 900 MHz modules but data I measured gave 17 mA at 13 volts. These operate over a wide voltage range so solar or battery operation is feasible. Both T and R have a "sleep" mode where the current is microamps. It would be more involved but the receiver could be wired to a simple timer and control circuit which would periodically wake it up to check for a signal as indicated by the RSSI output. This would cause the receiver to be on at higher current only when a signal is detected, functioning as a pseudo on/off remote controlled switch. With the low current drain this may not be needed but it is a neat option.
Neil
An after thought that I forgot to post. I have read conflicting information about the current requirements of the 900 MHz modules but data I measured gave 17 mA at 13 volts. These operate over a wide voltage range so solar or battery operation is feasible. Both T and R have a "sleep" mode where the current is microamps. It would be more involved but the receiver could be wired to a simple timer and control circuit which would periodically wake it up to check for a signal as indicated by the RSSI output. This would cause the receiver to be on at higher current only when a signal is detected, functioning as a pseudo on/off remote controlled switch. With the low current drain this may not be needed but it is a neat option.
Neil
Wow! Binged some info on these radios. Impressive. The average price is around $75 for a pair with charger. Walmart and Amazon advertize the package at $67.
The reviews on the radio itself are great but as stated here, the batteries are poor quality, replacable with standard Uniden headset battery packs or standard non-rechargable batteries.
The included headset/mic apparently is also of lower quality, not very comfortable.
Here is a LINK TO SPECS offered to view.
Wow! Binged some info on these radios. Impressive. The average price is around $75 for a pair with charger. Walmart and Amazon advertize the package at $67.
The reviews on the radio itself are great but as stated here, the batteries are poor quality, replacable with standard Uniden headset battery packs or standard non-rechargable batteries.
The included headset/mic apparently is also of lower quality, not very comfortable.
Here is a LINK TO SPECS offered to view.
I really enjoy your comments.
I think the TriSquare 900 MHz FHSS
radios were probably designed for
voice in the 300 - 3000 Hz range.
But to find out, the best thing would
probably be to call TriSquare and ask
them.
If they were able to pass high audio
fidelity, they would be the absolutely
perfect 900 MHz STL.
Except for one thing. My solar powered
49.83 MHz (For the prototype)/88.3 MHz
repeater will require a minimum of
energy. I have almost all the parts.
The prototype is just going to run when
it's in sunlight. But later, if I start fooling
around with charging circuits things will
be different. If the unit is going to repeat
24 hours (or even 12 or 18) it is going to
have to consume very little energy, or the
battery charge cycle will never be able to
keep up with the demand.
The TriSquare radio (from what I have read)
needs a fair amount of energy to operate.
On the other hand, the 900 MHz transmitter
and receiver modules that Neil suggested
don't appear to need much energy (especially
the receiver.)
So here we are. My first step is to get the
prototype working. I am buying a few parts
at a time. It will be running soon, I think.
Best Wishes,
Bruce, MICRO1690/1700
I really enjoy your comments.
I think the TriSquare 900 MHz FHSS
radios were probably designed for
voice in the 300 - 3000 Hz range.
But to find out, the best thing would
probably be to call TriSquare and ask
them.
If they were able to pass high audio
fidelity, they would be the absolutely
perfect 900 MHz STL.
Except for one thing. My solar powered
49.83 MHz (For the prototype)/88.3 MHz
repeater will require a minimum of
energy. I have almost all the parts.
The prototype is just going to run when
it's in sunlight. But later, if I start fooling
around with charging circuits things will
be different. If the unit is going to repeat
24 hours (or even 12 or 18) it is going to
have to consume very little energy, or the
battery charge cycle will never be able to
keep up with the demand.
The TriSquare radio (from what I have read)
needs a fair amount of energy to operate.
On the other hand, the 900 MHz transmitter
and receiver modules that Neil suggested
don't appear to need much energy (especially
the receiver.)
So here we are. My first step is to get the
prototype working. I am buying a few parts
at a time. It will be running soon, I think.
Best Wishes,
Bruce, MICRO1690/1700
I just saw your comments, thanks for sending
them.
I have to go right now, but I will have some more
comments, probably.
Thanks again,
Bruce, MICRO1690/1700
I just saw your comments, thanks for sending
them.
I have to go right now, but I will have some more
comments, probably.
Thanks again,
Bruce, MICRO1690/1700
I just went down to Radio Shack
and got 2 more solar cells. This
brings the number of 6V/50mA cells
up to 6 now.
More to follow.
Best Wishes,
Bruce, MICRO1690/1700
I just went down to Radio Shack
and got 2 more solar cells. This
brings the number of 6V/50mA cells
up to 6 now.
More to follow.
Best Wishes,
Bruce, MICRO1690/1700
Earlier Bruce MICRO 1690/1700 I think you mentioned you would like more information on how solar voltaic cells work. Maybe thi
http://www.sun-volt.com/pages/how.html
Earlier Bruce MICRO 1690/1700 I think you mentioned you would like more information on how solar voltaic cells work. Maybe thi
http://www.sun-volt.com/pages/how.html