Hi all...
Has anyone tested how wide the audio bandwidth is if tapping prior to audio filtering/amp...? (70 cm radio )
I understand there would be no standard figure...just a ball park idea would be good.....
audio bandwidth
Re: audio bandwidth
Good morning,
I'm assuming you're trying to run data at higher bit rates on a UHF radio here.
You could use discriminator audio, many commercial radios either have a discriminator output point or are easily modified to bring it out onto an accessory connector.
As for audio bandwidth, that would depend on many factors, but you would be able to get audio frequencies up to at least 6.25 kHz out with no de-emphasis.
I experimented a couple of years ago using Philips PRM80s and I was able to get up to around 38k4bps but the transmission wasn't clean at that rate and I wasn't able to acheive a link of any real distance with it.
I have since been able to do some wideband data experimentation (7-10 Mbps) on 70cm with completely different equipment, and reliably but that is understandably spectrum hungry.
I'm assuming you're trying to run data at higher bit rates on a UHF radio here.
You could use discriminator audio, many commercial radios either have a discriminator output point or are easily modified to bring it out onto an accessory connector.
As for audio bandwidth, that would depend on many factors, but you would be able to get audio frequencies up to at least 6.25 kHz out with no de-emphasis.
I experimented a couple of years ago using Philips PRM80s and I was able to get up to around 38k4bps but the transmission wasn't clean at that rate and I wasn't able to acheive a link of any real distance with it.
I have since been able to do some wideband data experimentation (7-10 Mbps) on 70cm with completely different equipment, and reliably but that is understandably spectrum hungry.
Tim, VK4TIM.
QG62MM, Brisbane.
QG62MM, Brisbane.