Re: [AFMUG] radio specifications... HOW?

rsday, September 21, 2017 12:11 PM >> *To:* af@afmug.com >> *Subject:* Re: [AFMUG] radio specifications... HOW? >> >> You are correct that wider front end filters give up masking and >> rejection of out of band interferers, but the intermediate frequency (IF) >>

Re: [AFMUG] radio specifications... HOW?

, Sep 21, 2017 at 11:15 AM, Chuck McCown <ch...@wbmfg.com> wrote: > I would add front end filter loss adds directly to noise figure which > affects sensitivity. > > *From:* Chris Gustaf > *Sent:* Thursday, September 21, 2017 12:11 PM > *To:* af@afmug.com > *Subject:* Re: [

Re: [AFMUG] radio specifications... HOW?

Thanks Chris, that helps point me in the right direction. On Sep 21, 2017 1:11 PM, "Chris Gustaf" wrote: You are correct that wider front end filters give up masking and rejection of out of band interferers, but the intermediate frequency (IF) and baseband filters are what

Re: [AFMUG] radio specifications... HOW?

I would add front end filter loss adds directly to noise figure which affects sensitivity. From: Chris Gustaf Sent: Thursday, September 21, 2017 12:11 PM To: af@afmug.com Subject: Re: [AFMUG] radio specifications... HOW? You are correct that wider front end filters give up masking

Re: [AFMUG] radio specifications... HOW?

You are correct that wider front end filters give up masking and rejection of out of band interferers, but the intermediate frequency (IF) and baseband filters are what determines RX sensitivity. In the case you outlined, if the channel width was say 56 MHz for both QAMs and the tuning range was

Re: [AFMUG] radio specifications... HOW?

It is my understanding that the larger the operational range of the radio, it is using vastly different filters to accommodate that range. These filters give up masking performance outside of the channel mask for an increase in range. Those wider range filters end up costing the radio

Re: [AFMUG] radio specifications... HOW?

In general for each increase in modulation level it requires about 3 dB more SNR (see below), and for each doubling of channel bandwidth you lose 3 dB sensitivity. SNR Requirements for Trango and others: QAM/SNR (dB) 256QAM/26.1 512QAM/29 1024QAM/32.5 2048QAM/35.8 4096QAM/40 The frequency

Re: [AFMUG] radio specifications... HOW?

I would rather not name the vendors at this time. On Sep 21, 2017 2:30 AM, "Mitch Koep" wrote: > Josh > > Will you shall the radio info? > > Mitch > > On 9/21/2017 12:57 AM, Josh Reynolds wrote: > > ​The frequency agility between the radios is 800 mhz. Vastly different > radio

Re: [AFMUG] radio specifications... HOW?

Josh Will you shall the radio info? Mitch On 9/21/2017 12:57 AM, Josh Reynolds wrote: ​The frequency agility between the radios is 800 mhz. Vastly different radio filters. Both are capable of similar channel bandwidths. This is all done at MCS0 / QPSK I'm comparing, basically, their

Re: [AFMUG] radio specifications... HOW?

​The frequency agility between the radios is 800 mhz. Vastly different radio filters. Both are capable of similar channel bandwidths. This is all done at MCS0 / QPSK I'm comparing, basically, their sensitivity and selectivity. The radio that is frequency capable of 200mhz is also capable of

Re: [AFMUG] radio specifications... HOW?

Can you give specific examples? Having a hard time understanding for sure the exact specs you're comparing. In relation to the thermal noise floor: just reducing from 1000mz to 200mhz will gain you ~7db of noise floor. But usually that's in a channel, not in the entire 'frequency agility'

Re: [AFMUG] radio specifications... HOW?

For clarification, at the same modulation rate AND at the same channel bandwidth. On Wed, Sep 20, 2017 at 10:19 PM, Josh Reynolds wrote: > Can someone smarter than I fill me in on something? I'm comparing some > radios here (no names...) > > One radio is 256 QAM, with a