Date   

Easiest/cheapest way to 6m/2m/70cm?

Max
 

I have Hermes Lite 2 which seems now to be working extremely well with SDRC as a very effective HF station and GC HF receiver.

Now I am looking to have a play with other bands, particularly 50 MHz, but also maybe 2m and 70cms. Just wondered if there are any opinions on how best to achieve this with SDRC and maybe also the HL2?

I can see there are some very well priced 6m/2m/70cm transverters from the Ukraine on eBay. Has anyone got any experience of these units?
https://www.ebay.co.uk/sch/221828490344

If not transverter (or perhaps a different model) then what else? I thought initially Pluto, but it does not seem to go low enough in frequency? Maybe 70 MHz but not as low as 50MHz?

Suggestions? I don't want to spend big bucks as usual! 

Many thanks

Max


Re: CW Skimmer decoded bandwidth

Max
 

Hi Grant

I never really looked at this before, but since you asked, I did what you suggest. Set a tuner frequency on CWS in the middle of a very active CW section (easy today..... CQ WPX!). Then I close CWS and re-open to make sure of a fresh start. open the station list and sort by frequency. 

No, I don't see any stations on the list that are outside the window I can see on the monitor, so for me, as you say, that is 22kHz. If I then retune on CWS to top of the list (which then centres it) I can then see the decodes on the fresh part of the "revealed" screen are only just starting. So no, it does not seem to decode any station that is outside of the visible window of 22kHz, for me at least. I don't see anything like the 48kHz that Bill has mentioned.

Bill, what there settings are there to adjust? I don't see any.

I must admit it made me think what CWS  is actually doing, and what the point is of the selectable sample rates if the window of received frequencies is limited to the visible window. I tried all three sample rates available 48 kHz. 96 and 192. I personally could see no visible difference in behaviour of CWS between any of them. I actually did the main test above set to 192kHz.

To be honest it's so fast to "scan" the active section by a quick scroll up and down the band on CWS to generate a full callsign list that I don't find it a restriction. Maybe it would be for a serious contester? I can fill a callsign list covering the full CW section of 20m in less than 30 seconds of "scanning" with CWS.

Hope it helps.

73

Max


On Sun, May 31, 2020 at 02:15 AM, Grant Rawstorn VK2LX wrote:
Are you getting a decoding bandwidth of greater than 22 kHz? In other words, for any set tuner frequency, if you view the list of decodes and sort the frequency column in the list, is there greater than 22 kHz or so between the lowest and highest?


Re: LimeSDR mini won't receive/transmit below 10 meters

MikeC
 

I believe the situation to be this:

 

The present version of Console does not support transmission below 30MHz with either the LimeSDR or the LimeSDR Mini. It did, but at some point that functionality became lost. A new version, I think is to be released next week, will re-instate this functionality. At present the receive below 30MHz works, but I found that only some sample rates worked when I tried it.

 

There is also a hardware issue with the low frequency input port where the matching is such that there is quite significant attenuation below 30MHz. There are various hardware mods to fix this, the simplest of which is removing a single inductor. This is the case for the LimeSDR, I am not sure for the mini. I have a Lime, not the mini, so I am not so familiar with the mini.

 

A sift through the previous posts here should make it clearer for you and a web search on LimeSDR below 30MHz will show the hardware mods.

 

Mike

 

Sent from Mail for Windows 10

 

From: Ken Swaggart
Sent: 30 May 2020 20:17
To: main@SDR-Radio.groups.io
Subject: [SDR-Radio] LimeSDR mini won't receive/transmit below 10 meters

 

Received my LimeSDR Mini last week and having fun trying out the various capabilities with SDR Console. Thought I would try WSPR on 30 or 20 meters but there doesn’t seem to be any transmit or receive below 28 MHz or so.  Thought it should go down to 10 MHz, but perhaps I’m missing a setting somewhere. Since I bought it to experiment on 23 cm and above it’s not a big problem.

 

Ken,

W7KKE

 


Re: CW Skimmer decoded bandwidth

Bill Alpert
 

48K or more with an IQ stream from the right rig. Settings are crucial to make it work.
--
73 de Bill / KG6NRV


Re: CW Skimmer decoded bandwidth

Grant Rawstorn VK2LX
 

Hi Max
I also observed this on my monitor and while I agree its odd, its not my main concern. Are you getting a decoding bandwidth of greater than 22 kHz? In other words, for any set tuner frequency, if you view the list of decodes and sort the frequency column in the list, is there greater than 22 kHz or so between the lowest and highest?
Cheers
Grant


Re: #LimeSDR Transmit Anomaly #limesdr

jose maria trueba
 

Hi Mike, Sigi and Joe,

Thanks for the 50ms hint, Mike. I will try it.

Sigi,
Your skyworks 20dB gain MMIC does look great. Mine is only 12dB gain, which means that I need to use 8dB more power from LimeMini than if I would replace my MMIC with the one that you've got.
I have three amplifiers after LimeMini, 12+21+17=50dB gain in all, so I need -10dBm from Lime to get 10w output power and -7dBm from LimeMini for my regular PEP which is around 20w with final linear amplifier working at 14VDC (I get around 50w at 26VDC). 

My unmodified Lime Mini does have a strong jitter, but it gets better after several minutes. I have mot seen any otjer Lime Mini carefully. I wonder if other people can see such a strong jitter as mine.A very unacceptable jitter comparing with Sigi's Pluto with TCXO replaced, and Joe's Lime SDR using an external OCXO.
I did check what happened if beacon is unlocked and I saw no differences. I sent another picture with neacon unlocked and we could see the drift but jitter was as bad as with the beacon locked.
I will try an external reference in the future (I already have two SMA connectors ready for this purpose fitted at the rear panel).

I do not see the central spur if Lime power level is set normally, to any output level lower than 10dB below max power, but I can see it if I push TX power to -5dB. I agree with Sigi that is better to set TX offset to 0KHz so we can see easily what happens with the spur. By the way I do not see it exactly at the frequency where an AM carrier would be located but around 900Hz below that point. I had no idea why but it must be that I had my XIT set to +860Hz, that must be the reason why most probably.

I have talked with Sigi several times after our very first and very short QSO, the first day that I went on air through QO-100. He is a very enthusiastic ham and it is always a pleasure to talk with him.
Yesterday Joe and I met for our first time and we had a super.interesting and long QSO until we had to quit to have lunch. I learnt many things including that Israel time is only one hour ahead of central European time. Really it's a pleasure to meet so many nice and very interesting people.
This sat is really something!

73,
jose, ea2jx



Re: Off Topic Request

David L. Wilson
 

On 5/29/2020 7:37 PM, David L. Wilson wrote:
Get the HackRF1. Yes, it can transmit but many only use it to receive. And there is software out there for it.  You are not going to find anything cheaper for what you want.  Chinese versions can be bought for about $150 in a case and they are fine. (In fact, sad to say, recently I was involved in a project where US manufactured versions had issues that the Chinese did not despite supposedly being the same design and the US cost more).
I have a LimeSDR Mini and a USRP but available software makes the HackRF1 the first choice.
I should have also added, you will not find anything cheaper that that nor will you find anything with more free useful software.

Programs that would with it include Universal Radio Hacker and (writen just for it) HackRF Sweep SA.

--
David L. Wilson


Re: Off Topic Request

Ray, W4BYG <w4byg@...>
 

I have a never used outside, California Amplifier phase locked block down converter for C-band 3.625 to 4.2 MHz, model 140001.  it has 20 db gain and requires +16 to 24 VDC at 250 ma. 
It outputs 950 to 1525 MHz.  It has an "N' female input and an "F" output.  20 degree noise temperature.  It was used only for a few lab tests.  I have the original data sheet.  It is missing the cover which would not be hard to replicate.

It is trading material, or make offer.  What have you?
Ray, W4BYG
37312

On 5/29/2020 21:50, martin m3ghe wrote:
Ideally you want a C band LNB, then you can use any of the radios you mention. But finding a cheap one maybe not so easy.

Martin

--
They say a smart person learns from their mistakes.  A
wise person learns from the mistakes of others.

Virus-free. www.avg.com


Re: #LimeSDR Transmit Anomaly #limesdr

jdow
 

That may not be particularly good for CW, AM, PM, FM, and digital modes. For SSB and SSB generated digital modes it's ideal.

{^_^}

On 20200530 08:48:25, MikeC wrote:
I agree about the levels. Anything above about -10dBm output causes distortion so there needs to be and amplifier for whatever you are using.
I also rather agree about the offset frequency, I always set it to 0Hz and then the spur is where your carrier would be in SSB. If the tx cal is done and the output level is not above -10dBm the spur is very low.
Maybe I was lucky with the hanging problem being solved by adding the 50ms tx delay, but it did fix it on the slower pc – I think....
This noise problem is the one that is causing me most concern at the moment particularly if you are running any power.
Mike
Sent from Mail <https://go.microsoft.com/fwlink/?LinkId=550986> for Windows 10


Re: For Simon Re AGC Questions Post (May 26; 56954) #sdrconsole

jdow
 

OK let's trace what it does as you increase the input amplitude and are not using hang AGC. That is the "oldest" form of AGC. At very low levels you have a fixed gain. As the signal goes up the demodulator input goes up. At some threshold the AGC becomes active. That's the AGC Threshold setting. As the signal goes up the input to the demodulator goes up less than the input. That's the slope. Some people like it dead flat, no demodulator level increase for input increases. Others like the audible hint that a slight slope gives, maybe 1dB output change for 10 dB input change. That is the slope adjustment rationale. There could be another setting for how fast does the AGC work on signal bursts. SDRC does not have this. Typically you want very fast capture of signal peaks. SDRC does have a control for how slowly the AGC action takes place. Does it drop really fast, as CW operators seem to prefer, or really slow, as SSB operators seem to prefer? That's the decay setting.

There is one more setting, hang. An AGC that is relatively flat, captures signal peaks, and stays there is nice for SSB. But, at some point one person stops talking and another starts, either at a higher or lower level. You'd like his signal to raise to a nice level if he's weaker than his predecessor. That is the hang AGC function. How long does it hold the last signal's setting before the gain goes back up.

There is one more automatic setting, how much gain exists for pure noise on the input? That's taken from the demodulator overload level, the all ones level of the analog to digital converter. It works down the "slope" and "threshold" lines to calculate a basic fixed gain in the system feeding the demodulator.

Note that I am discussing this in terms of an analog system, for the most part. That's what most people are familiar with. But say for SSB the AGC action could take place in floating point digital systems after the demodulator equally as well, and perhaps with less CPU load. The load reduction is really rather small compared to the overall SDR load so where AGC is performed seems to be rather fluid.

The SDRC AGC graph seems to be "common" to most programs I've seen. It simply visualizes the IF output to the demodulator versus the input signal level.

I hope this helped some. It needs editing and I'm too lazy right now to edit it myself.

{^_^}

On 20200530 03:56:54, rmrrgs wrote:
Hi Simon,
If you get a spare minute (Hah, Joke !) could you take a quick
look at my Post of May 26 "AGC Questions" (56954).
Would sure like to understand this a bit better.
(also, 56975)
Much thanks; appreciate your time and help,
Stay well,
Bob


LimeSDR mini won't receive/transmit below 10 meters

Ken Swaggart
 

Received my LimeSDR Mini last week and having fun trying out the various capabilities with SDR Console. Thought I would try WSPR on 30 or 20 meters but there doesn’t seem to be any transmit or receive below 28 MHz or so.  Thought it should go down to 10 MHz, but perhaps I’m missing a setting somewhere. Since I bought it to experiment on 23 cm and above it’s not a big problem.

 

Ken,

W7KKE


Re: #LimeSDR Transmit Anomaly #limesdr

josephlevy
 

Hi max zoom 20 lps
Single tone transmitted
High beacon (look at the part that only a single tone)


Re: #LimeSDR Transmit Anomaly #limesdr

Siegfried Jackstien
 

he see wobble also with no beacon lock ... (but then additional drifting)

please please ... do NOT use offset ... if there IS a spur ... you see it in your own if display (next to your passband) and you just do another tx calibrate (and spur should be gone or a lot lower) ... if you use offset ... then you may send the spur without notice (but may disturb on anotherones frequency) ... so best is to set that to 0hz ... and in case you see your own spur do a tx calibrate (do NOT FORGET TO SWITCH OFF AMP!!) ...

jose also measured how clean (or not) the lime is with different levels ... and he also wrote to stay 10 db or more below max power (and use another lna in the chain) ... in that level range gain is cheap :-) ... i use a skyworks65017 for around 20 db gain from 0.1 to 6 gig ... VERY nice broadband amp for a few mw out

first pic is jose

secondand third is my pluto ... first half with beacon lock on and second half beacon lock off

lnb is only tcxo modded and tcxo is INSIDE lnb but we have almost stable temp outside (cloudy and only a tiny bit of wind) so lnb drift is low

spectrum set to x8 resolution and 20 lines/sec on waterfall speed in first and 10 lines/sec on second picture

compare that with what jose sees ... his signal wobbles a lot more even if i do not count the maximum swings (100hz) but only the mean swings up and down (say 30 hz or so) ...

so all lime and maybe also pluto users ... please post a screenshot ... resolution x8 .. 10 to 20 lines wf speed and max zoom ... so we can compare the results (internal and external reference welcome)

joe ... may you also do the same test and post a screenshot??

greetz sigi dg9bfc



Am 30.05.2020 um 15:36 schrieb josephlevy via groups.io:

Hi Jose and Sigi
I can relate my experience with the LimeSdr USB

Do not transmit anything near the max power out.(signal is way distorted  then)
I set it to -20Dbm  (so needed another amplifier in the chain to reach the 2.4 Ghz for the Qo100)
But then it does not get stuck, no central spur (I use 250 khz offset) and see no spur anywhere on the full band of the Qo100)  (peak signal when modulating with a single tone S9+12
and nearly 37-8 S/N).
BTW   Jose I use now the X8 resolution on the waterfall and then you can see very accurately any Jitter in your signal, and mine is very similar to the band edge Beacon. If the 'lock to Beacon' is wobbling (a bit, not complete unlock) the you'll have wobbling on your TX freq.)

De Joe 4X1RV


Re: CW Skimmer decoded bandwidth

Max
 

Hi Grant

Quite a lot of people mention this as a limitation of CWS. The height of the window is fixed and there is no zoom feature (in or out) on the waterfall so you are stuck with whatever bandwidth you can view on your particular monitor.

For me I have two 1920x1200 monitors, but one of them I have in portrait mode. This was actually was for an totally different reason, but is often very useful, including for CWS because of course it is taller (1920 tall instead of 1200 of course). So for example on my main (landscape) monitor I can see about 12 kHz of spectrum on CW skimmer, but if I put CWS on my portrait monitor I can see nearly double.... about 22kHz.

Sorry, it seems this is the only solution. Odd but true, it seems.

73

Max


Re: #LimeSDR Transmit Anomaly #limesdr

MikeC
 

I agree about the levels. Anything above about -10dBm output causes distortion so there needs to be and amplifier for whatever you are using.

 

I also rather agree about the offset frequency, I always set it to 0Hz and then the spur is where your carrier would be in SSB. If the tx cal is done and the output level is not above -10dBm the spur is very low.

 

Maybe I was lucky with the hanging problem being solved by adding the 50ms tx delay, but it did fix it on the slower pc – I think....

 

This noise problem is the one that is causing me most concern at the moment particularly if you are running any power.

 

Mike

 

Sent from Mail for Windows 10

 

 


Re: #LimeSDR Transmit Anomaly #limesdr

josephlevy
 

Hi Jose and Sigi
I can relate my experience with the LimeSdr USB

Do not transmit anything near the max power out.(signal is way distorted  then)
I set it to -20Dbm  (so needed another amplifier in the chain to reach the 2.4 Ghz for the Qo100)
But then it does not get stuck, no central spur (I use 250 khz offset) and see no spur anywhere on the full band of the Qo100)  (peak signal when modulating with a single tone S9+12
and nearly 37-8 S/N).
BTW   Jose I use now the X8 resolution on the waterfall and then you can see very accurately any Jitter in your signal, and mine is very similar to the band edge Beacon. If the 'lock to Beacon' is wobbling (a bit, not complete unlock) the you'll have wobbling on your TX freq.)

De Joe 4X1RV


Re: Where is External Radio windows in Console V3?

Simon Brown
 

https://www.sdr-radio.com/external-radio

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Lopes Joao
Sent: 29 May 2020 23:45
To: main@SDR-Radio.groups.io
Subject: [SDR-Radio] Where is External Radio windows in Console V3?

 

I can not find how to start omnig integration to control external radio as I used to do with V2.
Thanks for support.
73
Lopes PY2SM


Re: #LimeSDR Transmit Anomaly #limesdr

Siegfried Jackstien
 

jose .. do not use offset ... not 25 and not 250 ... set that to 0hz!!

reason is ... that way the spur is next to your passband ... and you do not disturb on another frequency ...

(in my view simon should set default to 0hz)

dg9bfc sigi

Am 30.05.2020 um 14:21 schrieb jose maria trueba:

Yes. I have also seen very dirty transmitting most often and aclean signal sometimes. I do not know how.
Regarding the no transmission issue ... It used to happen quite often. Once every hour or so. Now with newest version of SDRC it happens very seldom with my i3 laptop running win10, maybe once every 5 hours, but if happens very often with my i5 running win7. I found out that transmission lacks audio, no Tune nor Tone either but if I push Drive all the way to 100% then I see that LimeMini is actually transmitting the DC central spur very visible 0.9KHz below the nominal transmitting frequency if TX offset is set to 0KHz instead the 25kHz default. 
By the way... How can I add your 50mw? I would love to try it.


Re: #LimeSDR Transmit Anomaly #limesdr

MikeC
 

I have two pcs. On the fast one (I7) I do not see the no transmission problem, but on the slower one (I5) I seem to see it often. It seems to not stop properly at the end of a transmission and therefore will not start another. Stopping or closing causes the program to hang.

 

I found that on my slow pc selecting 50ms on the tx streaming delay seemed to fix the problem and I could not make it do it. I have attached a picture of the setting screen. It is in Options, Radio Configuration. I found that any non zero delay here fixed it. I hope it solves that problem for you.

 

This noise problem is very strange, interesting that you may have seen a similar thing.

 

Mike

 

Sent from Mail for Windows 10

 

From: jose maria trueba
Sent: 30 May 2020 15:21
To: main@sdr-radio.groups.io
Subject: Re: [SDR-Radio] #LimeSDR Transmit Anomaly

 

Yes. I have also seen very dirty transmitting most often and aclean signal sometimes. I do not know how.

Regarding the no transmission issue ... It used to happen quite often. Once every hour or so. Now with newest version of SDRC it happens very seldom with my i3 laptop running win10, maybe once every 5 hours, but if happens very often with my i5 running win7. I found out that transmission lacks audio, no Tune nor Tone either but if I push Drive all the way to 100% then I see that LimeMini is actually transmitting the DC central spur very visible 0.9KHz below the nominal transmitting frequency if TX offset is set to 0KHz instead the 25kHz default. 

By the way... How can I add your 50mw? I would love to try it.

 


Re: Simon's World Map 1.0.9

Siegfried Jackstien
 

he should get a sheep or two

dg9bfc sigi

Am 30.05.2020 um 12:58 schrieb Jerry Lofstead:

Simon,
You sure have a lot of grass to cut! 8=)

On Sat, May 30, 2020 at 12:34 AM Simon Brown <simon@...> wrote:

Hi,

 

TX: resonant dipole,
RX: Wellbrook loop

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of John FitzGerald
Sent: 29 May 2020 21:25
To: main@sdr-radio.groups.io
Subject: Re: [SDR-Radio] Simon's World Map 1.0.9

 

What antennas are you using on 80 Meters Simon , I am very interested in this project . 

de EI9HW 

 

On Wed 27 May 2020 at 18:42, Simon Brown <simon@...> wrote:

What do you do when it's too hot for SDR coding? You update Simon's World Map to v 1.0.9, that's what.

 

https://dit-dit-dit.com/world-map

 

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

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