Dongle performance among samples


#1

Has anyone detected a difference in performance from one identical model dongle to another ? Say one FA Pro+ to a second Pro+ ( or third, etc…) with otherwise identical config ?

Curious as to whether there is any evidence that some may perform better than others due to small manufacturing ( component tolerances) differences. I know that there are a lot of variables that make direct comparisons difficult, but as I’m swapping antennas and messing about I started staring at the dongle itself scratching my chin.


#2

If they are the same model, and from close manufacturing batches, I don’t think you’ll see differences.

One thing to consider is electrostatic discharge. I don’t know how good a protection, if any, the FA dongles have, but other dongles are very sensitive to it. I had a Pro+ that seemed to have gone partially deaf. Electrostatic discharges are very common up here in the winter. They are actually visible, believe it or not.

I seem to recall reading that the FA orange dongles may have differences from early to current batches. If memory serves, the first batches included an LED, later batches do not. That alone makes a difference in current consumption and heat generation. There may have been other changes, since it was the first dongle released by FA.


#3

Many years ago I dealt with ESD issues when installing mainframe computers. I am actually surprised how comparatively robust modern components are- today I regularly see people ham-fistedly grabbing memory SIMs and the like and jamming them in without consequence. We used to have to use an ESD mat with ground cords and a wrist strap to touch any logic components whatsoever…and even then “stuff” happened.


#4

I worked in a telecoms office in a previous life. There were all sorts of equipment in there. One of them was an OC48 fiber node that was very sensitive, even to the touch.

The manufacturer could not find the reason for it. Parts/cards/modules were replaced, a lot of money was spent on grounding and bonding. ESD mats installed around it, ESD straps, you name it.

We were even afraid to look at it, in case some bad energy from us would trigger a failure.

This thing looked like a religious totem after a while, for all the respect and fear it commanded from us techs.

Again, a big office, and only this one node was acting up.


#5

I was looking for a photo of some of the gear I once worked with. Shocked to find that there is actually an example in a museum, which sort of suddenly makes me feel very old !

http://www.computermuseum.org.uk/fixed_pages/IBM3084.html


#6

Already tested that… barely perceivable difference between the FA Pro Plus dongles, Had three Pi’s running off of one antenna with 3 Pro +'s for power consumption testing (for remote sites, ongoing project), swapped about several times. It did change slightly if the dongle ran hotter ie in a box or even upside down which i put down to frequency drift of the chips. There was a slightly worse result from the old style dongle… but i put that down to the connectors being a good bit older and maybe suffering from oxidisation as that particular one used to be housed near the sea in a weather station.

They are susceptible to a small amount of Solar Panel interference just incase anyone is wishing to do that sort of project… site them at least 1m away!

I wish i had taken pics as i had around 15 or so Pro and Pro+'s at one point :slight_smile

I can relate to the OC48 node issues you had, a speciality paper factory that i did my training in had sensors that were very much like that. Very sensitive to static and any spikes from motors… the manufacturer tried several versions to solve it. Ended up getting all changed to a different brand when we changed severs and systems making them incompatible. No issues after that… They for what they were back then were awfully expensive per unit!


#7

Thanks - I suspected they were probably fairly consistent but don’t have the means to test out the theory. And I’m learning a great deal about operating a remote station…definitely some complexities and compromises involved !


#8

i have my dongle wrapped in aluminum foil, i did a few test with the skyview running and watching my message count number, it calculated small amount but adds up. my calculation come to about 5% increase in messages, and when taking off to cross check it went down. i made sure to have aluminum foil also wrapped on end connector of coax to ground out.


#9

That’s slightly different. Improving shielding does not mean different performance among samples.

There is no doubt that the dongle can be improved, at a cost. If you don’t mind adding an external amp and filter, the RTL-SDR Blog dongle is a better option.


#10

@Dxista I see RTL-SDR Blog also offers an LNA Bias-T amplifier as well. I have searched here on this board but not yet found many reviews of it at all.


#11

I have one, and it’s excellent, provided you don’t mind having to deal with bias-T. That is, either using a receiver that is bias-T capable, or adding a power inserter, as it does not have a power in connection, barrel or USB.

By the way, it also includes a filter, double or triple, I don’t remember now.


#12

Thanks for quick response. Something I might try in the future if I can gain some antenna height with a longer coax. I suspect one of my locations is always going to be tree and horizon limited but I am not yet getting anywhere near the results I expect there with any of my homemade antennas, nor the FA stick with LMR400.


#13

@XE3N7NAT,
I bought 4 or 5 metal dongle cases from the rtl-sdr.com shop a few years ago(they no longer sell them).
The FA dongles fit in them perfectly. I believe they helped with some noise at my location.