NGC 2666 Open Cluster testing 5 meter USB3 cable

[menardre]

One of the problems with USB3 is that the cable length is usually limited to 2 meters. This poses a problem for observatories since (at least in my case) the computer is more that 2 meters away.

One problem that I have found using longer USB3 cables is that my ZWO ASI camera will get stuck in 'Downloading Image' process. This is usually due to USB bus traffic and USB3 timing. I have tried to solve this problem by using a longer (5M) active cable. I have tried a few different active cables and found one that works. I recently found an article in which a non-active USB3 5M cable was used with success. This is the 'Lindy Cromo' cable. So I decided to give it a try. I bought a 5 meter Lindy Cromo USB3 cable and ran some tests.

First I just connected to my ZWO ASI2600 and took a bunch a sample images with exposure of 30 seconds. No problems. But this does not really simulate real world conditions in which the bus traffic includes PHD2, iOptron mount, Optec focuser, as well as camera.
So last night I decided to image the open cluster NGC 2666 with the new cable. There is nothing really special about NGC 2666 except that it is located in a good part of the sky and I could get a couple of hours of imaging (clouds were due in later in the evening).

So I set everything up as usual, however I used the new 5 meter Lindy Cromo vice the active USB3 cable. It should be noted that the new cable connects directly to the camera, while the active cable connects to a shorter USB3 cable which then connects to the camera.

I took 64 images of 2 minutes using the new cable with no problems. Then I took 50 flats (0.1 sec) with no problems. It was a good test of the new cable and everything worked perfectly. Download speed was increased. I am going to continue testing the new cable.

So, if anyone was a problem trying to use a longer USB3 cable, so far the Lindy Cromo looks like a decent solution.

This image is NGC 2666 open cluster taken with SVX130 refractor and ZWO ASI2600 OSC camera. I used PixInsight for processing and used SubframeSelector to eliminate images with higher than normal FWHM or eccentricity. Very basic image processing since no details to try and bring out. As you can see, nothing to write home about - very sparse open cluster.

Roger

NGC 2666_Master_DBE_SPCC_BXT_NXT_HT_CurvesSat.jpg (9.79 MiB) Viewed 927 times

[AstroGeek]

Hi Roger,

I ran into this problem with USB 3.0 a couple of years ago. With the purchase of two ZWO webcams (color & mono), I wanted too be able to hook up the camera out in the dome and run the signal into my basement office. I've used a powered USB 2.0 powered extender for years to send CCD signal back-n-forth. Well, I found that the webcam signal over USB 2.0 was very slow and clunky. I did quite a bit of research on USB 3.0 extension cables. Finally settled on the one below, which is 100 feet long and not powered at all. It works at the same speed as if I was sitting out there next to the camera with a computer. It was pricey, but for indoor lunar, solar, and planetary imaging it is worth it! The cable presently runs from my mount, through the observatory wall, underground for 50 feet, enters the house, up the wall, above the ceiling, down the wall, and to the back of my computer.

https://sewelldirect.com/products/light ... 4981674030

[menardre]

Steve

Glad you solved your USB problem. I have never seen an optical USB cable before, but it certainly should solve the problem of long distance USB3 transmission.

It is pricey,,,,, but anything that solves a problem is worth it.

Thanks for sharing

Roger