Topics

Lime on HF


Michael Durkin
 

Ok peeps,

Send Boyce has been trying to get his lime to work on HF for a while now and I just tried I think is somewhat recent build and I'm looking at confucio range not being described in the correct spot to spand that It can do ... I thought you can do 30 megahertz to 3.8 gigahertz or 60 megahertz to 3.8 gigahertz ...

Not sure if I can send pictures through a groups.io but I'll give it a shot ..

The small screen SDR is on correct freq ... i also have a ft-757gz not in picture also on 7.1mhz LSB that I listen with. 



Siegfried Jackstien
 

the local can tune down to 30 megs

then you sample with 60 megs (gives you plus minus 30 from local)

that is the normal way ...

how low could you tune local of the lime (besides that is it then used out of spec)?!?!

dg9bfc sigi

Am 22.01.2019 um 06:07 schrieb Michael Durkin:

Ok peeps,

Send Boyce has been trying to get his lime to work on HF for a while now and I just tried I think is somewhat recent build and I'm looking at confucio range not being described in the correct spot to spand that It can do ... I thought you can do 30 megahertz to 3.8 gigahertz or 60 megahertz to 3.8 gigahertz ...

Not sure if I can send pictures through a groups.io but I'll give it a shot ..

The small screen SDR is on correct freq ... i also have a ft-757gz not in picture also on 7.1mhz LSB that I listen with. 



Michael Durkin
 

Ill try again tonite ....

one of the problems with having the sample rate so high .. is that i
cant Demod SSB worth a hoot with 10Megs of displayed bandwidth ...

On 1/22/19, Siegfried Jackstien <siegfried.jackstien@...> wrote:
the local can tune down to 30 megs

then you sample with 60 megs (gives you plus minus 30 from local)

that is the normal way ...

how low could you tune local of the lime (besides that is it then used
out of spec)?!?!

dg9bfc sigi

Am 22.01.2019 um 06:07 schrieb Michael Durkin:
Ok peeps,

Send Boyce has been trying to get his lime to work on HF for a while
now and I just tried I think is somewhat recent build and I'm looking
at confucio range not being described in the correct spot to spand
that It can do ... I thought you can do 30 megahertz to 3.8 gigahertz
or 60 megahertz to 3.8 gigahertz ...

Not sure if I can send pictures through a groups.io <http://groups.io>
but I'll give it a shot ..

The small screen SDR is on correct freq ... i also have a ft-757gz not
in picture also on 7.1mhz LSB that I listen with.





Edouard Griffiths
 
Edited

Not sure the device to host has to be 60 MS/s (I would have to browse through LMS7002M specs again). If this sample rate is only needed at the ADC then you can play with the hardware decimation. When pushed at its maximum of 32 a device to host sample rate of 2 MS/s is enough to get 64 MS/s at the ADC. Then you can move that 2 MHz window with the NCO and bandpass filter it with the hardware FIR.

Edit: yes it is exactly like that. The RF mixer with its LO down to 30 MHz is located before the ADC hence it is the ADC that has to run at 60+ MS/s. So you may well set the hardware decimation at 32 (5 stages) and run at 2 MS/s in software. It will be easier on the device to host link as well. You still have to further tune inside the band below 30 MHz with the NCO. Note that the hardware LPF has to be set at 60 MHz minimum (maybe a bit more if you tune really low so as not to hit too much the filter corner). The FIR is centered on the NCO frequency so you can use it to filter out the unwanted signals in the band below 30 MHz. Strong signals may still affect reception as the LPF is open wide so you need to use a hardware filter up front which is always advisable when using SDRs. An antenna tuner may play this role as well.


Siegfried Jackstien
 

hello edouard

just to tell you something

i was arguing about that sdrangel does not work on my "crappy old laptop" (an older core2dou with 2 gig ram and win7)

that was long time ago (version 3.1.something?!? cant exactly remember)

now i installed newest windows version ... and what can i say ... IT WORKS!!! how wonderful :-)

tested with pluto

more tests to come for sure (do not now if that old machine is fast enough also for tx with the pluto but will try)

greetz

sigi dg9bfc

Am 23.01.2019 um 09:34 schrieb Edouard Griffiths:

[Edited Message Follows]

Not sure the device to host has to be 60 MS/s (I would have to browse through LMS7002M specs again). If this sample rate is only needed at the ADC then you can play with the hardware decimation. When pushed at its maximum of 32 a device to host sample rate of 2 MS/s is enough to get 64 MS/s at the ADC. Then you can move that 2 MHz window with the NCO and bandpass filter it with the hardware FIR.

Edit: yes it is exactly like that. The RF mixer with its LO down to 30 MHz is located before the ADC hence it is the ADC that has to run at 60+ MS/s. So you may well set the hardware decimation at 32 (5 stages) and run at 2 MS/s in software. It will be easier on the device to host link as well. You still have to further tune inside the band below 30 MHz with the NCO. Note that the hardware LPF has to be set at 60 MHz minimum (maybe a bit more if you tune really low so as not to hit too much the filter corner). The FIR is centered on the NCO frequency so you can use it to filter out the unwanted signals in the band below 30 MHz. Strong signals may still affect reception as the LPF is open wide so you need to use a hardware filter up front which is always advisable when using SDRs. An antenna tuner may play this role as well.


Siegfried Jackstien
 

hmmm

why can i tune the tx part of the pluto just below 47 megs ...

and the rx only down to 70 megs???

greetz

sigi dg9bfc


Am 23.01.2019 um 09:34 schrieb Edouard Griffiths:

[Edited Message Follows]

Not sure the device to host has to be 60 MS/s (I would have to browse through LMS7002M specs again). If this sample rate is only needed at the ADC then you can play with the hardware decimation. When pushed at its maximum of 32 a device to host sample rate of 2 MS/s is enough to get 64 MS/s at the ADC. Then you can move that 2 MHz window with the NCO and bandpass filter it with the hardware FIR.

Edit: yes it is exactly like that. The RF mixer with its LO down to 30 MHz is located before the ADC hence it is the ADC that has to run at 60+ MS/s. So you may well set the hardware decimation at 32 (5 stages) and run at 2 MS/s in software. It will be easier on the device to host link as well. You still have to further tune inside the band below 30 MHz with the NCO. Note that the hardware LPF has to be set at 60 MHz minimum (maybe a bit more if you tune really low so as not to hit too much the filter corner). The FIR is centered on the NCO frequency so you can use it to filter out the unwanted signals in the band below 30 MHz. Strong signals may still affect reception as the LPF is open wide so you need to use a hardware filter up front which is always advisable when using SDRs. An antenna tuner may play this role as well.


Edouard Griffiths
 

These are the specs of the AD9364 (assuming you did the trick of making Pluto think it has a AD9364 instead of AD9363).


Siegfried Jackstien
 

ahh .ok ... thank you

i thought rx and tx are the same and so was wondering why this difference

ok now to do some more testing :-)

...

greetz

sigi

Am 25.01.2019 um 09:44 schrieb Edouard Griffiths:

These are the specs of the AD9364 (assuming you did the trick of making Pluto think it has a AD9364 instead of AD9363).