WB-SG1 wide band generator

[Grandchuck]

This unit just arrived so needs more testing.  As a preliminary report, all seems to work as expected.  Amplitude accuracy is nothing to rave about but is acceptable; the frequency accuracy is very good.  The operation range of frequencies is as advertised.

Channel 2 can be modulated by Channel 1, as shown below.

[Diabolo]

Hello,

Ok.
The CH1 frequency of 100 kHz will modulate the CH2 frequency (1080 MHz) by this value (100 kHz) if the "MOD" function of CH2 is ON.
The WB-SGI generator is sold +/- 145 $ / 135 € on Aliexpress, or Ebay.

Serious seller and fast shipping.
- https://fr.aliexpress.com/item/4000468601984.html?spm=a2g0w.12010615.8148356.22.11f0d5c7pfHHq1

------

The name WB-SG1 would suggest that a version # 2 "WB-SG2" could appear with all the options that are absent on the WB-SG1, but it would be more expensive to buy.
The FA-1 frequency counter was followed by the FA-2 frequency counter.



Diabolo

[Diabolo]

Hello,
It would be interesting to see the level of harmonics with a spectrum analyzer that I do not have available. If anyone could make these measurements they would be welcome.
----
What about an FM modulated signal on CH2 ?
For example, a fundamental signal modulated in FM with a deviation of 25 kHz is not likely to resemble an FM signal with a deviation of 100 kHz.

Regards
Diabolo

[Grandchuck]

Here is the spectrum of channel 2 from 35 MHz to 1.5 GHz.  How does one obtain FM?

[Diabolo]

Thank you for the answer.
-----
The manual says that CH2 modulated by frequency CH1 is a CH2 signal modulated in FM.

Diabolo

[Grandchuck]

My document states:  CH2 modulation: ON/OFF modulation, modulation frequency 1Hz-1MHz, step 1Hz

[Diabolo]

ADF4351 produces a 2.2 GHz sinusoidal signal at 4.4 GHz, and produces a square signal from 35 MHz to 2.2 GHz by division of the frequency.
------
How is the spectral purity of a 750 MHz signal on CH2 which will therefore be a square signal loaded with harmonics?

Diabolo

[Grandchuck]

The spectrum of an unmodulated 750 MHz signal is shown below.

Does anyone know of any software in the works for this generator?

[Diabolo]

Hello,
Thank you for the test.
With the WB-SG1 I only got summary documentation without the access codes via USB to obtain certain information or to be able to change some internal data. The FA-2 frequency counter had a few command lines provided to change certain parameters. The web is not very talkative about WB-SG1, alas.

Wait for reviews from other buyers.


Regards

[mankan]

There is a WB-SG-OPT15G available now, see https://www.aliexpress.com/item/4000724122338.html. No modulation feature though. I guess it's based on LMX2594. I wonder if there will be a LMX2595 version later?

[Diabolo]

Hello,

New frequency generator 1hZ at 15 GHz from BG7TBL called WB-SG1-OPT15G 1hZ at 15 GHz! The output level setting is adjustable compared to the 8 GHz model with the output level fixed.
https://www.ebay.com/itm/WB-SG1-OPT15G-1Hz-15GHz-Signal-Source-Signal-generator-Power-ADJ-OCXO-BG7TBL/233507852253
-----
Characteristics:
overview:1Hz-15GHz wide band output,10M-15GHz with amplifiler adjust,OCXO inside，
support extern connectfrequency stanard
CH1 frequency range：1Hz-200MHz
CH1 step:1Hz-19.999999MHz/1Hz,20MHz-200MHz/10Hz
CH1 output amplifiler:3.3Vpp
CH1 plug type:BNC
CH2 frequency range：10MHz-15GHz
CH2 step:10Hz
CH2 reference output power：+5DBM- -7dBm@1G
CH2 output impedance:50 OHM
CH2 plug type:SMA
inside frequency stadnard:10MHz
inside frequency stadnard type:OCXO
inside frequency stadnard ageing:0.5Hz/year
10M frequency output power:5dBm
extern frequency input range:0dBm to +20dBm
run mode:CH1 frequency mode,CH2 frequency mode,CH1 sweep mode,CH2 sweep mode
front panel:MODE,change mode
ENT:input data
<>^V:left/right/up/down key
CH1:channel 1 output
CH2:channel 2 output
rear panel:10M REF INPUT:extern 10M input
10M REF OUTPU:10M output
USB:USB port
STD ADJ:inside OCXO frequency adjust
power switch
dc plug
power :DC11.7-12.5V,star:less than 0.5A,stabilize:less than 0.25A
size:L*H*D=106*55*105mm
weight:350g
accessory: DC12V adapter 1pcs

Regards
Diabolo

[noreply]

Hello,

New frequency generator 1hZ at 15 GHz from BG7TBL called WB-SG1-OPT15G 1hZ at 15 GHz! The output level setting is adjustable compared to the 8 GHz model with the output level fixed.

CH1 plug type:BNC
CH2 frequency range：10MHz-15GHz
CH2 step:10Hz
CH2 reference output power：+5DBM- -7dBm@1G

Does anyone have the 15Ghz device?

It would be really nice to verify if indeed there is ability to control the 'output level' in dBm

Looking at the 'specifications'  - as provided on the eBay listing (very limited) - it specifies an output level RANGE (in my humble opinion) and not that it can be 'user defined' 

Remember - output energy is likely to be much higher at lower frequencies - than at 15GHz - so the CH2 reference output power：+5DBM- -7dBm@1G does make sense.

Note - it only specifies -7dBm @ 1GHz

I wonder what it is likely to be at 15GHz?

If it is indeed a decent figure - I am sure that the published specifications would be boasting about it!

The fact that output levels @ 15GHz are not specified - is an indication itself - that there is nothing to shout about 

Perhaps someone with an actual device could chime-in 

[noreply]

There is a WB-SG-OPT15G available now, see https://www.aliexpress.com/item/4000724122338.html. No modulation feature though. I guess it's based on LMX2594. I wonder if there will be a LMX2595 version later?

Seen a device on eBay already (its not a BG7TBL design) ...

https://www.ebay.com/itm/LMX2595-10MHz-19GHz-RF-Signal-Generator-Frequency-Source-Sweep-OLED-Software-/183730920473

- with these specifications 

1, LMX2595 chip features
• 10MHz to 19GHz output frequency
• With 100KHz offset and 15GHz carrier
-110dBc/Hz phase noise
• 45fs RMS jitter at 7.5GHz (100Hz to
100MHz)
• Programmable output power
• PLL main specifications
– Quality factor: –236dBc/Hz
– Nominal 1/f noise: –129dBc/Hz
– highest phase detector frequency
– 400MHz integer mode
– 300MHz fractional mode
– 32-bit score N divider
• Eliminate integer boundary spurs with programmable input multipliers
• Output phase synchronization across multiple devices
• Support for SYSREF with programmable resolution of 9ps resolution
• FMCW's frequency ramp and chirp capability
• Less than 20μs VCO calibration speed
• 3.3V single supply operation
2, LMX2595 chip application
 
• 5G and millimeter wave wireless infrastructure
• Test and measurement equipment
• Radar
• MIMO
• Phased array antenna and beamforming
• High speed data converter clock (supports JESD204B)

Looks like from their SA plot @19GHz - the output level is -26dBm and there seem to be 'lots' of harmonics in the 'same' region 

Can you really have a reliable 19GHz source without special design considerations and PCB / microstrip factors implemented for a $385 price tag?

Does anyone have this device or made any tests with a LMX2995 design?

Any feedback much appreciated

[noreply]

Just went down the rabbit hole on the LMX2595 ...

https://www.ti.com/product/LMX2595

That a full development PCB with access to design software (so you can drive this beast) is only $399

Interesting thing is that the LMX2595 device itself is $55 (in 1000 lot)

Looking at the evaluation design - the PCB / connectors / associated electronics / your fabrication and testing time and application software - its not bad value - if you want to build your own stuff - or adapt the EVAL board to your needs.

In the UK - here is link from distributor ...

https://www.mouser.co.uk/ProductDetail/Texas-Instruments/LMX2595EVM?qs=EU6FO9ffTweu4F9rUl5PJQ%3D%3D

Here is the user guide ...

https://www.ti.com/lit/ug/snau219b/snau219b.pdf


At the moment - I simply don't have the time or mindset to go further down this fascinating 'rabbit hole' - however your individual mileage might vary 

Good Luck & Hope above information was useful.

[noreply]

Looking further into the modulation capability of this device ...

It appears that the frequency set in CH1 will modulate the fundamental frequency set in CH2 - Provided that CH2 out=on and MOD out=on

I had the impression you could modulate the fundamental of CH2 by connecting source to BNC on CH1

I guess this is not how its intended to operate - too bad - it would be a much more flexible device if this was possible and you could use the settings of CH1 as the FM frequency deviation (BW)

Anyone 'opened-up' one of these devices - to see what makes it 'tick'

(I still have not had a chance to do this - just got it today and there is lots of other things which need my attention before I get to the screwdrivers)

- more importantly if there is any way to inject any external modulation?

Great device - I checked the frequency - its clean - harmonics well below fundamental - will do some measurements soon.

Real useful check is to do some phase noise measurements - if no-one has done this already   

[mankan]

Stumled across this one eBay auction: #114332851333. Looks like there are 18 and 20GHz options available now.

Output power is now specified further:
1G/8DBM;2G/7.3DBM;3G/8DBM;4G/8.7DBM;5G/9.9DBM;
6G/8.5DBM;7G/4.5DBM;8G/5.2DBM;9G/4.4DBM;10G/3.4DBM
11G/4.3DBM;12G/4.6DBM;13G/3.0DBM;14G/3.0DBM;15G/1.7DBM
16G/-1.4DBM;17G/-4.9DBM;18G/-6.4DBM;19G/-6.5DBM;20G/-8.3DBM

[g4dbn]

Has anyone found if there are commands which the WB-SG1 will interpret?  At boot time it shows:

WB-SG1
1Hz-8GHz
SIGNAL GENERATOR
CH1:1Hz-200M CH2:35M-8G
BG7TBL V20191203

but despite trying to fuzz it and lots of keyboard mashing, I couldn't get it to respond at all via the serial/USB.

I can set the frequency via the front panel at up to about 8.7 GHz as you'd expect, but it seems to go a bit flaky at certain frequencies above 8.5 GHz.

This little box could be quite useful with a levelling amplifier and programmable attenuator and filters and a proper decent interface and a proper modulator, but I'm not scrapping my HP E4421B yet.

Neil

[noreply]

@g4dbn

Hi Neil,

Welcome to the forum 

I have the WB-SG1 and am attaching a user manual for you to look through - if you don't have one already.

I found this device useful - but only for general experimentation.

If you are relying on it to make meaningful measurements - where power levels are important - forget it - its simply not up to the job, despite your idea of leveling amplifier and programmable attenuator.

I looked into this myself and to get an 'accurate' programmable attenuator is a challenge in itself - let alone to 8GHz

- same applies for the leveling amplifier

- now you know why a decent RF signal generator costs big $'s

I also draw you attention to the spectral quality of the signal from the WB-SG1 - its not so pure if you had a closer look with a SA

But despite all of the above - its still a very handy tool for simple testing - where 'empirical measurements' are not important.

[texaspyro]

I have the WB-SG1 and am attaching a user manual for you to look through - if you don't have one already.

I don't see an attachment... 

[noreply]

I have the WB-SG1 and am attaching a user manual for you to look through - if you don't have one already.

I don't see an attachment...

So Sorry 

It should be there now 

[g4dbn]

My google-fu was not up to standard, thanks v much for the copy of the manual.  I want to try it for checking the return loss and tuning of some 3.4 and 5.7 GHz feedhorns, using directional couplers, so the absolute level isn't critical.  I'll be using a specan as the detector, so I'm not worried about harmonics and far-out spurs confusing matters.  It'a a whole lot easier than using a set of YTOs.  Might even be enough signal to use the second harmonic to check the SMA-WR90 transitions I'm machining today.
TVM Neil

[noreply]

My google-fu was not up to standard, thanks v much for the copy of the manual.  I want to try it for checking the return loss and tuning of some 3.4 and 5.7 GHz feedhorns, using directional couplers, so the absolute level isn't critical.  I'll be using a specan as the detector, so I'm not worried about harmonics and far-out spurs confusing matters.  It'a a whole lot easier than using a set of YTOs.  Might even be enough signal to use the second harmonic to check the SMA-WR90 transitions I'm machining today.
TVM Neil

Sounds good.

The WB-SG1 does produce a signal on frequency, but since it has an external 10MHz input, if you use a 10MHz GPSDO - then you will be 'spot-on' frequency if that's important to you when aligning feedhorns or any associated filters.

[Kibabalu]

Has anyone found if there are commands which the WB-SG1 will interpret?  At boot time it shows:

WB-SG1
1Hz-8GHz
SIGNAL GENERATOR
CH1:1Hz-200M CH2:35M-8G
BG7TBL V20191203

but despite trying to fuzz it and lots of keyboard mashing, I couldn't get it to respond at all via the serial/USB.

I can set the frequency via the front panel at up to about 8.7 GHz as you'd expect, but it seems to go a bit flaky at certain frequencies above 8.5 GHz.

This little box could be quite useful with a levelling amplifier and programmable attenuator and filters and a proper decent interface and a proper modulator, but I'm not scrapping my HP E4421B yet.

Neil

I also failed to establish any kind of communication with the WB-SG1 via USB/serial. What's the trick?

[hpw]

  how this signal generator performs in terms of PN.... low freq. range and on 10MHz?

[videobruce]

Is there a actual manual of the original device in the 1st few posts, NOT the TI device which only has a engineering/builders manual?