David for free DV etc How are you dealing with differences in clock speed for TX to RX ?
Does the RX sample-rate-convert to its local domain, or does it follow the incoming sample clock (and hence adjust its own clock ) ? On 1/08/2015 12:54 PM, David Rowe wrote: > Sounds like you have it about right Michael! > > On 01/08/15 11:36, Michael Carey wrote: >> Hi David, >> >> I get virtually the same results with the microphone connector as I do >> with the ACC connector. Other things like TBW (transmit bandwidth) are >> disabled with you enable the Data mode but I'm sure there is still >> processing/DSP in the audio path... the IC-7100 is that kind of radio. >> >> It appears to be working pretty good, but I'm just not confident on the >> output power. The only thing that seems to be consistent and may be >> what I follow... is the PA current indication. >> It doesn't jump around all over the place and shows a nice steady 5-6A >> which would be about right for 20-25W RF output. >> >> I've tried a different RX radio (TS-140S) just to see if that would make >> a difference... but no. >> >> Michael. >> VK5ZEA >> >> On 1/08/2015 8:19 AM, David Rowe wrote: >>> Hi Michael, >>> >>> SNR sounds similar to what I get from my IC7200. I think yr close. >>> >>> Only issue with using the data connector is levels. The SM1000 output >>> is attenuated quite a lot down to typical mic levels (see SM1000 page >>> for specs). So maybe check the levels are compatible. >>> >>> Cheers, >>> >>> David >>> >>> On 01/08/15 08:09, Michael Carey wrote: >>>> Thanks for the info David, >>>> >>>> I'm hoping to find others who are using the SM1000 and FreeDV with the >>>> Icom IC-7100 radio and compare what we've done. >>>> >>>> I am flying a bit blind with setting the power levels. I'm presuming >>>> that both the radio power output meter and my external wattmeter don't >>>> "like" the FDMDV modulation to give a true power output indication. I >>>> set the radio power output at 25% (once again presuming that 100% is >>>> 100W! :-) ), I increase drive so that ALC just indicates and I get >>>> around 3-5 W showing on the power output meter... but it's not steady, >>>> jumping around all over the place. >>>> >>>> I'm modulating via the ACC connector on the back of the transceiver, the >>>> IC-7100 has Data mode which when selected allows you to take audio from >>>> different places... in my case the ACC connector. This also turns off >>>> compression and other trickery that might mess with a data transmission. >>>> >>>> I'm using a Kenwood TS-50, SignaLink (non USB version) and a Cmedia >>>> sound card in my shack PC to decode the IC-7100. >>>> >>>> I get 0 BER, SNR of 17, but the spectrum display looks a little lumpy. >>>> I can fiddle with the output of the SM1000 over a fair range with very >>>> little change in the displayed signal and received audio. The scatter >>>> diagram also doesn't look as nice as I've seen others. The dots are >>>> most certainly grouped together, but not as tight as I would have liked. >>>> >>>> I'm hoping to get more time in the shack this weekend to experiment a >>>> bit more. >>>> >>>> 73 >>>> >>>> Michael. >>>> VK5ZEA >>>> >>>> On 26/07/2015 7:19 AM, David Rowe wrote: >>>>> Hi Michael, >>>>> >>>>> FB on getting your SM1000 up on the air - lets have a QSO some time! >>>>> >>>>> Adjusting so your ALC just moves, and 20-25 watts average power for a >>>>> 100W PEP rig is a useful rule of thumb for FreeDV 1600. The classic >>>>> "rookie mistake" is overdriving the SSB tx, which causes clipping and a >>>>> poor bit error rate at the receiver. Make sure any speech compression >>>>> is off too. >>>>> >>>>> The best way to adjust your tx drive is monitor the SNR of the signal >>>>> using a 2nd rx and the FreeDV GUI program. For example when I tx with >>>>> my IC7200, I have a FT817 nearby with no antenna and the RF gain wound >>>>> down. I feed the rx audio into my laptop and monitor the scatter >>>>> diagram and SNR. Incidentally, with my IC7200 I can't seem to get >>>>> better than 20dB, perhaps due to it's sharp tx filtering. >>>>> >>>>> I have a video that demonstrates this (and explains scatter plots): >>>>> >>>>> http://www.rowetel.com/blog/?p=3109 >>>>> >>>>> Cheers, >>>>> >>>>> David >>>>> >>>>> On 25/07/15 23:05, Michael Carey wrote: >>>>>> Hi Everybody, >>>>>> >>>>>> I've been building up a set of SM1000 cables for a few of my different >>>>>> HF radios. The main radio I use at home is an Icom IC-7100. >>>>>> I understand you set the input level to the radio so the AGC indication >>>>>> barely moves and make sure you don't stress the output stage too much... >>>>>> I've settled on around 30W output. >>>>>> >>>>>> I find that the AGC indication on my IC-7100 tends to jump around a >>>>>> little when transmitting the FDMDV signal. >>>>>> Can I use the test tone to set the transmit level and be confident that >>>>>> this is OK for FDMDV? >>>>>> >>>>>> 73 >>>>>> >>>>>> Michael. >>>>>> VK5ZEA >>>>>> >>>>>> ------------------------------------------------------------------------------ >>>>>> _______________________________________________ >>>>>> Freetel-codec2 mailing list >>>>>> [email protected] >>>>>> https://lists.sourceforge.net/lists/listinfo/freetel-codec2 >>>>>> >>>>> ------------------------------------------------------------------------------ >>>>> _______________________________________________ >>>>> Freetel-codec2 mailing list >>>>> [email protected] >>>>> https://lists.sourceforge.net/lists/listinfo/freetel-codec2 >>>>> >>>> ------------------------------------------------------------------------------ >>>> _______________________________________________ >>>> Freetel-codec2 mailing list >>>> [email protected] >>>> https://lists.sourceforge.net/lists/listinfo/freetel-codec2 >>>> >>> ------------------------------------------------------------------------------ >>> _______________________________________________ >>> Freetel-codec2 mailing list >>> [email protected] >>> https://lists.sourceforge.net/lists/listinfo/freetel-codec2 >>> >> >> ------------------------------------------------------------------------------ >> _______________________________________________ >> Freetel-codec2 mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/freetel-codec2 >> > ------------------------------------------------------------------------------ > _______________________________________________ > Freetel-codec2 mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 > -- - Glen English RF Communications and Electronics Engineer CORTEX RF & Pacific Media Technologies Pty Ltd ABN 40 075 532 008 PO Box 5231 Lyneham ACT 2602, Australia. au mobile : +61 (0)418 975077 ------------------------------------------------------------------------------ _______________________________________________ Freetel-codec2 mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freetel-codec2
