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?

Hi Ross,

What version of fldigi are you using. I've been running it for a while
and I have been completely unaware it would work with I-Q radios (SDR).
Did I overlook something? Maybe there is a config setting in a later
version. I can't find anything in the one that is running on my computer
now.

73,

Bill KU8H

On 04/25/2014 02:14 AM, Ross Sanders wrote:
> Thought I'd put in my 2c worth on this one. FLdigi has a OS-X port of
> it's software suite. You can find it on
> and I do know you can use hamlib to support Softrock radios. There is
> an OS-X port for hamlib it says on the development website. I
> personally use fldigi for my HTX-10, no rig control of course, but I
> like the program itself even compared to the large number of offerings
> on Windows. I also use it on Windows. I don't have any personal
> experience with OS-X but as a general thing, if it works on unix-like
> systems it often will work on OS-X.
>
> Ross
> KD0VHN
>

-- 
Sid Boyce ... Hamradio License G3VBV, Licensed Private Pilot
Emeritus IBM/Amdahl Mainframes and Sun/Fujitsu Servers Tech Support
Senior Staff Specialist, Cricket Coach
Microsoft Windows Free Zone - Linux used for all Computing Tasks

Ordered the "SoftRock Lite II Combined Receiver Kit" from fivedash.com and received it
yesterday.? Project not starting off well, I am having trouble following the instructions.

I'd like to construct a 40m version of the SDR.

Went to the specified web site for instructions and the title says
http://www.wb5rvz.org/softrock_lite_ii/index/projectId=8
Softrock Lite II Home - Softrock Lite II RX

* Have I found the correct instructions?
* Is the "SoftRock Lite II Combined Receiver Kit" same as "Softrock Lite II RX"?

* A thorough read of the documentation shows only Band: 20m

Not sure why the instructions specify a 20m band on portions of the doc which don't
even seem to be band specific.

Under the instructions for BPF, I see a link for band specific chart.
http://www.wb5rvz.org/softrock_lite_ii/05_bpf
But the chart says "original, pre-June 1, 2010 kit".
http://www.wb5rvz.org/softrock_lite_ii/band_specific.gif

* Where is the band specific chart for a *recent* board?

I am confused, can anyone offer guidance please?

Thanks
Roger

Hi Ross,

What version of fldigi are you using. I've been running it for a while and I have been completely unaware it would work with I-Q radios (SDR). Did I overlook something? Maybe there is a config setting in a later version. I can't find anything in the one that is running on my computer now.

73,

Bill KU8H

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Hi Syd,

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Thanks John.

?I know that I can compile and build it on Linux. I have two Linux VMs (Parallels 9 for Desktop), one running Ubuntu 13.04, and another with Debian 7.

For me, the real challenge is to build it on the native OS.

I have now to assume that nobody has yet succeeded to build on OS X, and that I am on my own.

73 de Jean-Paul (AC9GH, ex F5KT)

On Apr 24, 2014, at 2:43 AM, John Rabson <john.rabson07@...> wrote:

My son suggests "Try running Linux as a guest OS in VirtualBox (hosted on the Mac). I can’t make any promises, however.”

73

John F5VLF

From: Jean-Paul Louis <louijp@...>

Subject: Re: [softrock40] quisk starting to work...

Date: 21 April 2014 05:14:36 CEST

To: softrock40@...

Reply-To: softrock40@...

Hi Sid,

I have been lurking into this group for several years, and I see how people

refers to you as the Quisk expert for Linux builds.

I am trying to build Quisk not on Linux, but on Mac OS X.

Do you know if anybody has successfully built quick on OS X?

My builds failed because I do not have ALSA on a Mac, but quick is supposed

to work with port audio which is available on the Mac.

I posted my question on the N2ADR group as N2AR is supposedly the one who wrote

quisk, but all my posts were ignored.

I just need to know what to change to use portaudio, as right now every build complains

about a missing alas header.

73 de

Jean-Paul

AC9GH @ EN61vr99

louijp ? at ? yahoo ? dot ?com

-- 
Sid Boyce ... Hamradio License G3VBV, Licensed Private Pilot
Emeritus IBM/Amdahl Mainframes and Sun/Fujitsu Servers Tech Support
Senior Staff Specialist, Cricket Coach
Microsoft Windows Free Zone - Linux used for all Computing Tasks

David

Again we miscommunicate.

The only measurements for which I use HDSDR are for signal levels, and then only after after calibration against a -73 dBm standard. Any noise readings from HDSDR are completely irrelevant except, as you have noted, for relative comparisons.

The only absolute noise measurements I make are directly on the I Q outputs of the RXII. It is at this point that I can say the absolute noise output is 2 dB higher with the LO/mixer engaged than it is without. Since both measurements are taken after the gain of the op amps it is clear there is no value to adding op amp gain or reducing op am noise because the noise from the mixer is masking the op amp.

Noise and signal plus noise measurements for purposes of calculating MDS are made as recommended by ARRL at the speaker terminals and are relative, not absolute.

Warren Allgyer
9V1TD

David

(I hope this is not a double post.... I replied but an hour later I don't see it here)

I think we have a miscommunication. -130 dBm is the signal level that resulted in a 3 dB S+N/N value as measured with an RMS voltmeter at the audio output. The actual noise level at that point was significantly below -140..... I did not note it but I think around -148 dBm. And that floor appears to have been set by the mixer/LO combination, not the op amps since when I disconnect the USB drive to the LO that floor drops by 2 dB.

So, in my RXII as currently configured, if I increase the op amp gain I cannot increase S+N/N because the additional gain will pull the mixer/LO noise up the same amount as the signal.

Warren Allgyer
W8TOD

David

My Peaberry V2 is 9000 miles away operating as W8TOD by VNC so I cannot duplicate your tests.

You mention however that you are using HDSDR for your measurements. You can get some fantastic performance numbers if you dial the RBW back, average the noise floor, and read MDS as a 3 dB spike above the averaged noise. Frankly I think this is a more valid methodology for DSP based receivers than is the ARRL method.

But the results will not correlate with the ARRL method. A 3 dB spike above an averaged noise floor on HDSDR will be perfectly audible but it will not result in a 3 dB S+N/N ratio at the audio output. In fact, if memory serves, there was no significant difference between S+N and N on an RMS noise meter under those circumstances.

If you are using output RMS noise as your measurement then I can only guess that something about the Peaberry mixer/LO layout produces less noise than does the Ensemble II and, therefore, "uncovers" the op amp noise to allow for improvements.

Warren Allgyer
9V1TD (and W8TOD through the magic of VNC)

Interesting stuff Roger!

I think there are improvements that can be made in the op amps. What has led me to put that on hold is the evidence that the overall receiver noise figure, in a lab environment at 10 meters, seems to be set by the mixer/LO switching mechanism. I have observed that the noise is 2 dB higher with the mixer enabled than it is when the plug is pulled. This means that any improvement in the noise performance of the op amps has no benefit for MDS improvement.

It does seem to me that there may be 5-6 dB of headroom improvement available if the op amp power supply could be raised from 5 - 10 volts since the limiting factor on the high end seems to be the signals banging into the 2.5V rails on either side of virtual ground. I had planned to try that in conjunction with improving the op amp noise but have lost interest at the moment and refocused on the front end for possible improvements there.

Warren Allgyer
9V1TD

Warren, the new equip. is great! Since I am sure you are eagerly looking for new mods to try the new equip on, here is a suggestion. :)

The op amps think they are connected to + and - V supplies and see everything referenced to the non-inv. input, which with real + - V supplies is usually "ground". The SoftRocks however use a single +5 V supply with a divider to place the non-inv. input at +2.5 V. This becomes the reference for the op amp circuit. With real + - V supplies, the + and - rails are each bypassed well to "ground". With the divider system, one would expect both rails to still be bypassed to the reference, which is now the +2.5 V divider formed by R27 & R28 for the Ensemble II. The schematic shows that this common point is bypassed to the - rail ("ground" now) with 0.1 and 4.7 uF caps. However, the + (+5V) rail is not bypassed directly to the common point, it is bypassed to "ground" with C45, a 0.1 uF cap, and C5, a 4.7 uF cap. The + rail bypass would have to go by an indirect route thru these two caps and then thru the - rail bypass caps back to the common point. To see whether a direct bypass would improve performance, I bypassed the R27/R28 junction to a close +5 V spot with a 0.047 uF disc ceramic and a 2.2 uF audio quality electrolytic cap (I did not have a 4.7 uF). I do not have equip at hand to measure MDS. Looking at the spectrum display on SDR-Radio, this change lowered the noise level with the USB plug removed by about 3 dB. If this represents the op amp noise level, then this is an improvement. The noise level with the USB connected (mixer running) was not changed however, so maybe the MDS has not changed.

Interestingly, adding these caps resulted in the 60 Hz center spike dropping (with the laptop running on battery, not connected to AC mains) 20 to 25 dB.

I then changed the + rail bypass to a 100 uF cap and added a second 100 uF to the - rail (i.e. in parallel with the existing 4.7 uF bypass). I could not see a difference from the single 2.2 uF.

So, Warren, if you are interested in adding a couple caps to your board and repeating your measurements, it would be very interesting to hear what you find. BTW, it will be necessary to rebalance the image rejection, as I found that changing this bypass situation changed the balance.

Roger

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Thanks John.

Here is a headline: I am conceding this disagreement to Alan!

Through a fortunate but very coincident set of circumstances I acquired a wonderful instrument over the weekend: An Amber 3500 "Distortion and Noise Measuring Set". This is a broadcast quality instrument and just happens to be the very unit that we used to do broadcast proof of performance at KRON TV in the early 90s. A power supply repair, general cleanup, and meticulous calibration later, I have a great new toy.

This makes MDS testing a piece of cake as it reads RMS noise levels directly down to -130 dBV. So the new number for MDS for my RXII is -130 dBm at 28.1 MHz with a 500 Hz bandpass for a 3 dB S+N/N ratio.

Here is where I have to concede to Alan's golden ear and intuition:

In order to get good noise readings I connected directly to the Line In connector of the RXII, eliminating both the sound card and the software. With the Amber I am able to narrow down to a 500 Hz bandpass and read the actual RMS noise on the I or Q channel. Very interesting results:

-66 dBV RMS Noise with a tuned, outdoor 10 meter dipole connected and tuned to 28.1 MHz

-92 dBV RMS Noise with the antenna terminated in a dummy load.

-94 dBV RMS Noise with the USB plug removed, eliminating the mixer.

-110 dBV RMS when 12V power is removed from the RXII

My conclusion, based on these numbers, is that the op amp gain is just about perfect as it is designed and there is no benefit to fussing with it.

A preamp will not help me because of the very high environmental noise. But for those like Alan who do not get a noise rise when the antenna is connected, it appears that a preamp or a better antenna or both are needed to optimize 10 meter performance.

As always I welcome input on the methodology or the conclusions.

Warren Allgyer
9V1TD

Original Message -----
Subject: [softrock40] Re: RXTX sparking and arcing (still having waveform issues)

I connect the usb to the computer, the power cable to the power strip the computer runs on, and two 3.5mm audio cables between the board and a creative xfi pro.

You are connecting the Softrock "Line In" to the soundcard Line In?
Have you gone over all the voltages and tests so far? "Sparking and arcing" worries me.

73 Alan G4ZFQ

Original Message -----
Subject: Re: [softrock40] Re: softrock40

Try changing R32 and R33 to 10k instead. You can leave C23 and C24 off for
testing.
By doubling the feedback resistors you are halving any OpAmp noise that
loops back into V-. If this doesn't help then I'd guess you hit a limit
due to common mode noise.

Spice says you will get an extra 6dB up to 10KHz if you leave the capacitors untouched. About 4dB down at 30KHz.
My tests suggested there was no SNR improvement.

73 Alan G4ZFQ