Rf Signal Generator or SDR?

[KD6VXI]

I have an sdrplay on its way.   Plan on an anan based unit next year.  So this isn't a question of is this a good sdr...

Need an rf signal generator that is more stable than the heathkit tube ones I have for a project coming up.

Looking online,  for a digital one that goes to a hundred mhz,  it's at least 150 bucks.

For 199.99 one can get a HackRF One.   1mhz to 6ghz TX / rx sdr. It's 8 bit,  but it does what I need.  From the YouTube videos I've seen,  the hackrf does indeed go down to the am broadcash band,  so half mhz is doable.

Would make a nice signal injector / limited spec an is my thoughts...

Don't have a spectrum analyzer,  do have a scope and audio generator,  so those are covered.   Need something that will generate accurate and stable rf to about a hundred mhz.

Any thoughts or other ideas?   I've also given thought to needing an IPA between the hackrf and test subject,  as a buffer if nothing else.

--Shane
KD6VXI

[flintstone mop]

I have been very satisfied with the Elecraft XG3 sig gen.

Stable and good enough for Ham use. Good for checking calibration of sig level readouts on the SDR carrier meter and general RF snooping around. May not be 'lab standard' ....but good enough for Ham radio stuff

https://www.google.com/search?q=elecraft+xg3&ie=utf-8&oe=utf-8

http://www.eham.net/reviews/detail/9807

https://www.youtube.com/watch?v=vhrW4UkJ2_U

[KD6VXI]

Fred,

I was about to pull the trigger and buy it,  did everything I need.  Looked at the video,  literature,  etc.

Until I got to Elecraft price.   For 20 bucks more,  I can buy the HackRF.  The elecraft does 1.4 ghz ,  the sdr box does 6.

That's my dilemma....  I guess I'm wondering if anyone has used a sdr like this as a sig gen....

--Shane
KD6VXI

[Pete, WA2CWA]

Can't remember the last time I wanted to calibrate something at 3 or 4 GHz.  

I like the fact that the XG3 is programmable with four calibrated output levels and two programmable sweep functions.  Great for sweeping IF chains and diddling with FM receivers. This thing would be great for measuring sensitivity, calibrating your S-meter, adjusting the RF front ends, and probably other whizzy things I can't remember.

The HackRF seems to designed as a bench diddling box. Software diddle with this, software diddle with that, etc. If you're a SDR bench diddler, this would probably be a good product. At least one customer reviewer indicated that the front-end receiver sucks.

But one does what one wants to do with what's at hand. I can recall several times over the years using my IC-756 PRO II as a low power generator to do a RF alignment. Also with Elecraft, if you have a problem with the product, you can pick up the phone and give them a call.

[flintstone mop]

Can't remember the last time I wanted to calibrate something at 3 or 4 GHz.  

I like the fact that the XG3 is programmable with four calibrated output levels and two programmable sweep functions.  Great for sweeping IF chains and diddling with FM receivers. This thing would be great for measuring sensitivity, calibrating your S-meter, adjusting the RF front ends, and probably other whizzy things I can't remember.

The HackRF seems to designed as a bench diddling box. Software diddle with this, software diddle with that, etc. If you're a SDR bench diddler, this would probably be a good product. At least one customer reviewer indicated that the front-end receiver sucks.

But one does what one wants to do with what's at hand. I can recall several times over the years using my IC-756 PRO II as a low power generator to do a RF alignment. Also with Elecraft, if you have a problem with the product, you can pick up the phone and give them a call.

Great points , Pete
I found better performance with an SDR, softRock radio with the calibrated output of the XG3 to set the input level control of the audio device to get close to the S reading in the display's S-meter. Check several bands to see that it's relatively close for each band. Turning the level control on the audio device to full will bring up a lot of noise. I may be back in the dark ages with SDR's. I don't know if there's an I/Q output from the newer generation or there's still a need of a hi-end audio device.

What we're saying here, the XG3 is simple and good. Stable for ham use.

[W6MQI]

The XG3 is okay for most use things I didn't like were cumbersome to operate, doesn't go below 100Khz show stopper for me, I think it had to be run through a attenuator to adjust the output beyond what was available on the front panel presets.  One sorta gets what one pays for.

[MikeKE0ZUinkcmo]

Reminds me of the proverb from the mid-1500s "you can't make a silk purse out of a sow's ear", or more recently "...puttin lipstick on a pig".  

If you want the functionality of a signal generator, spend the money and get a good "Signal Generator".   They're real test equipment, and are in the same price range, or not much more than the solutions discussed so far.   And best of all, are designed specifically for the tasks discussed.

Mike