Spectrum Analyzer - Rigol DSA815

[TurboTom]

@airlomba

I made a DIY return loss bridge that performs quite well. You find some information about it here: https://www.eevblog.com/forum/testgear/siglent-ssa3000x-spectrum-analyzers/msg1013579/#msg1013579

If there's serious demand for a more detailed instruction on how it's constructed, I may prepare a write-up and post it here (or maybe in a thread of its own).

Merry Christmas,
Thomas

[airlomba]

@TurboTom

Thank you for the reference of your RLB, from what I've read in the topic you pointed, it an excellent bridge. I already am looking for the parts in order to build one like yours. If I have troubles, I'll come back to you. Again, thank you.

@ted572

It look like you have done a good job on your SA. However, I feel that I am missing something here. Please forgive me for my probable lack of vision. If the shunt between pins 7 and 8 is to write protect the FRAM, in order to keep the trials infinite, why did you use a switch? I mean, what is the point of reopening this shunt? In which case, would it be interesting/useful to be able to write to the FRAM again? Thank you.

Best regards,
Emmanuel.

[ted572]

The Rigol Firmware 00.01.18 Installation Notes state that this version 'Doesn't support downgrade back to previous FW versions'.
This statement is only valid for the newer DSA815's with Boot Loader version 00.01.04.

DSA815's with Boot Loader 00.01.02/3 still allow installation of the previous Firmware versions.
If you are interested in the required method please see the provided attachment.

[Nebulex]

First of all I would like to thank  all of you who contributed to finding a way to make the DSA815 hackable. 

@572
I looks like when ever I change something that needs to be written in to the FRAM i.e the IP address the actual timerr value of the trail version counter are going to be written to the FRAM.


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[Nebulex]

this Text should have been attached to the last message but I accidentally hit send to early   

Here at my findings about the upgrading to firmware 00.01.18. They might be useful for the ones of you who are in doubt if an upgrade is good option. I had pin 7 and 8 shunted on my DSA815 with boot version 00.01.04  and could therefore stay on 27 hours of trail time for the options. Just before upgrading from firmware 00.01.16 to 00.01.18 I removed the shunting between pin 7 and 8, upgraded and the trail time was set to 0. After letting my SA stay on for exactly the time that was left before the trail timer was set to 0 the 36 hours of trail time reappeared after reboot.

[Nebulex]

If you shunt pin 7 and 8 after your trail time reappeared it still counts down but after a reboot it will always start right at the time after shunting the pins. So with boot version 00.01.04 you can also keep the trail time for ever  

[ted572]

RF ‘Return Loss Bridge’ Suggestions for the DSA815-TG user on a limited Budget

I listed below two Chinese RF Return Loss Bridge units that are available from ebay at reasonable prices that generally meet their advertised Return Loss specification of 35 dB minimum. The advantage in these two units is that they are supplied in rugged aluminum cases, and can be opened easily for tweeting/improving their return loss performance.  As supplied they perform much better than the popular Mini Circuits directional coupler that a lot of the Hams are using, or even the expensive Rigol model VB1020 VSWR Bridge (a nice looking package, but with poor performance and specifications).
I’m not affiliated in any way with these suppliers, and simply wanted to offer some easy to work with suggestions for Return Loss Bridges for those that may be interested in something that works relatively well for a very reasonable investment cost.   
1. This is a Chinese Return Loss Bridge for 1 to 500 MHz that is rated at -35dB Return Loss that can be purchased for about $40 USD.  Although, I suggest (Item 2.) the 1 to 1,000 MHz unit below for about $20 USD more for its extended frequency range, nicer construction, and easier to work on while assembled.
Example: http://www.ebay.com/itm/NEW-1-500-MHZ-reflection-bridge-standing-wave-bridge-rf-bridge-/291539579585?tfrom=302125570443&tpos=top&ttype=coupon&talgo=undefined
2. This is a Chinese Return Loss Bridge for 1 to 1,000 MHz that is rated at -35dB Return Loss that can be purchased for about $60 USD.  This one is my preferred choice due to its being easier to adjust for improved performance than the 1 to 500 MHz unit above.
Example: http://www.ebay.com/itm/NEW-1-1000MHz-1GHz-reflection-VSWR-bridge-bridge-bridge-RF-SWR-bridge-/131329059012?hash=item1e93d268c4:g:RY4AAOSwr81USGVL

Caution: Do not do any adjustments or tweaking if you do not have a excellent 50 Ohm Termination such as a Mini Circuits (MCL) model KARN-50-18+, N male connector, 2 Watts, DC to 18GHz, $14 each (brand new, directly from Mini Circuits).  Also do not make any adjustment if your not fully familiar with a Return Loss Bridge, haven't Normalized your SA with the RLB (with a 'UUT' Open) between the TG Output and SA Input.  If in doubt , don't do anything to your new RLB!
Even without any adjustments these units should perform very well for you.
Additional reference info:  https://www.eevblog.com/forum/testgear/spectrum-analyzer-rigol-dsa815/msg583550/#msg583550
See the (*.doc) attachment for RLB pictures and a Response Plot of the 1 GHz unit.

[ted572]

Using the DSA815-TG 'Power Sweep' Mode to Measure a RF Active or Passive Device's Linearity.  e.g. RF Amplifier, Mixer, RF Limiter, etc.

[orin]

How could you use a KARN-50-18+ to adjust one of these?  The minimum return loss for the KARN-50-18+ is 35dB for DC-1MHz according to the Mini Circuits data sheet.

[ted572]

How could you use a KARN-50-18+ to adjust one of these?  The minimum return loss for the KARN-50-18+ is 35dB for DC-1MHz according to the Mini Circuits data sheet.

Hello 'orin':  Where did you get that a 'KARN-50-18+ is 35dB for DC-1MHz' from?
The Mini Circuits KARN-50-18+ is specified to be typically better than 40 dB Return Loss from DC to 6 GHz.  And I have never seen one that didn't have a 50 dB Return Loss up to 1 GHz, and often up to 2 GHz.  I know that they are not specified to be this good, but Mini Circuits has always provided these to us with much better performance than they specify.  Yes, even by 10 dB better at these lower frequencies.  Anyway I'm confident that they will work great for the devices we are concerned with here.
KARN-50-18+ Specification is attached below.

[orin]

How could you use a KARN-50-18+ to adjust one of these?  The minimum return loss for the KARN-50-18+ is 35dB for DC-1MHz according to the Mini Circuits data sheet.

Hello 'orin':  Where did you get that a 'KARN-50-18+ is 35dB for DC-1MHz' from?
The Mini Circuits KARN-50-18+ is specified to be typically better than 40 dB Return Loss from DC to 6 GHz.  And I have never seen one that didn't have a 50 dB Return Loss up to 1 GHz, and often up to 2 GHz.  I know that they are not specified to be this good, but Mini Circuits has always provided these to us with much better performance than they specify.  Yes, even by 10 dB better at these lower frequencies.  Anyway I'm confident that they will work great for the devices we are concerned with here.
KARN-50-18+ Specification is attached below.

The minimum spec. in the datasheet.

Sure, the ones you tested may well be 50dB return loss (As a point of interest, what standard did you use to compare with?  Even the HP 909C/F with N connectors I have would struggle to can't do that.), but unless you can verify a given unit, you cannot assume it's better than the minimum spec. in the datasheet which is 35dB return loss.

So, whereas I feel you could use a KARN-50-18+ as a standard to get a reasonable degree of confidence that a bridge specified at 35dB return loss is OK, I don't think it's a good idea to adjust a bridge to match a KARN-50-18+'s return loss unless the KARN-50-18+ has been verified against a better standard.

I suppose I could order a KARN-50-18+ or two and see what they look like on an 8753C, but as I said, I don't have standards good enough to measure a 50dB return loss.

[ted572]

SMA Finger Wrench: If you use SMA connectors you may be interested in a SMA Finger Wrench.  I recommend the one below, but with the easy modification that you can do to them as shown in the attached images.
Bracke 'SMA Finger Wrench' P/N BM30012 at -> http://www.brackemfg.com/  And please note that they will currently supply up to five (5) free samples to qualified users.
You can see details of the SMA Finger Wrench here -> http://www.ebay.com/itm/SMA-Finger-Wrench-plastic-20-pieces-per-order-/322392860356?hash=item4b101ca6c4:g:H2oAAOSwo4pYfQ-G

[razvanm]

Hi guys,

I run a DSA815-TG unit with :

Version of Main Board: 00.04
Version of Radio Frequency Board FPGA: 00.05
Version of Digital Board FPGA: 00.04
Version of Firmware: 00.01.09
Version of Boot: 00.01.02

Can somebody please share the firmware files for 00.01.09 and 00.01.12? Links on the previous posts are broken and I got a strange answer to my update request from Rigol.

I need the older files in case my unit will refuse to boot after an unsuccessful upgrade to 00.01.16.

Thank you!
Razvan

[razvanm]

Received a PM with everything needed. Thank you!

[pa4mic]

Hi all,

I follow this great thread for some time but now have an question because i'm not 100% sure how to handel at this moment.

I have boot version 00.01.04 with firmware 00.01.09, the main board version is 00.08, radio board 00.05, digital board 00.04 and want to update to the latest firmware 1.18 version. The FRAM is write protected with 35hours of trails left.

-The first question is can i update from 1.09 directly to 1.18 without problems or do i need to make an step between is first?

-The second question is when i update to 1.18 must i leaf the FRAM protection in and after that the trails will be set to zero and then let the sa on for at least 10 hours or must it 35hours as i read some where? After that the trails will be alive again?

-And the last one is there still some one working on an new hack and need some dumps to help or something els, i'm willing to help with that where i can.

Thx all

Michael

[N8AUM]

pa4mic

I think I read in a previous post that ver 18 WILL NOT allow you to downgrade so you end up losing whatever options are being kept safe with the FRAM's pins 7 & 8 shorted. You will lose options when going to version 17 but if you need them you can go back to version 16

good luck !!!

73  N8AUM

[Nebulex]

@pa4mic
Remove the FRAM protection, upgrade to 1.18 then you will lose your trail option for exactly the time that was on your trail counter. After that trail time will reappear.  You can shorten the FRAM again and keep the trail time. See also my posts #870 - #872. This worked on my DSA815.




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[videobruce]

Anyone interested in a 815TG in MINT condition with around 100 hrs PM me. (US only) 

[Daruosha]

I'm pretty much confused with minimum RBW figures of DSA815. On Rigolna.com, the minimum RBW is mentioned at 10Hz, on rigol.eu and int.rigol.com, it has been mentioned at 100Hz, on all online manuals, it's 10Hz, but in all reviews people saying it's 100Hz.

Recently i bought a new unit and it goes down to 10Hz, but in spans more than 150KHz, it shows UNCAL sign when I reduce the RBW to less than 30Hz.

Same confusion applies for DANL and phase noise. What's going on with Rigol?!?

Also somewhere in the forum i read there some SCPI commands to read and dump the memory of the device. I wonder can I use the same technique we used to unlock DS2000 series scope to generate the keys for DSA815? shorting the pins is not the best idea when it comes to warranty and future risks.

[Daruosha]

I'm pretty much confused with minimum RBW figures of DSA815. On Rigolna.com, the minimum RBW is mentioned at 10Hz, on rigol.eu and int.rigol.com, it has been mentioned at 100Hz, on all online manuals, it's 10Hz, but in all reviews people saying it's 100Hz.

Recently i bought a new unit and it goes down to 10Hz, but in spans more than 150KHz, it shows UNCAL sign when I reduce the RBW to less than 30Hz.

Same confusion applies for DANL and phase noise. What's going on with Rigol?!?

Ok, found the answer. It was a new feature added from firmware 1.17.  Rigol websites are a mess.

[geggi1]

Hi all!
I guess this is a stupid question.
I have  a DSA 815TG with boot version 00.01.04 with firmware 00.01.09. and no time left on the trial options.
If i upgrade to a newer firmware will the trial options timer be reset?

[airlomba]

Hi all!
I guess this is a stupid question.
I have  a DSA 815TG with boot version 00.01.04 with firmware 00.01.09. and no time left on the trial options.
If i upgrade to a newer firmware will the trial options timer be reset?

Hi,

I don't ahve the experience necessary to answer correctly your question, but I think that since your trial periods have ended, you have nothing to loose by updating your firmware. In fact, you'll get the 10Hz RBW!

Kind regards,
Emmanuel.

[Daruosha]

Hi all!
I guess this is a stupid question.
I have  a DSA 815TG with boot version 00.01.04 with firmware 00.01.09. and no time left on the trial options.
If i upgrade to a newer firmware will the trial options timer be reset?

Updating firmware has no effect in your time-trial options. If your options are expired, you won't gain extra time or anything else.

[geggi1]

I was hoping that it might reset the trial timer  :-)

[danny_isr]

I'm in the same boat as you. This thread is a bit long and hard to follow what is the bottom line. I have one that still in trail. And would like to know as well.