Small HD 502 with Fs700 + O7Q

M

Minh

Active member
Hello everyone,

I just bought the SmallHD 502. I might need some of your help to figure out what's happening here..

So the FS700 feeds the SDI signal to the O7Q, but when I output the SDI out of the 7Q to the 502, there's no signal...
But when I output HDMI out of the 7Q to the 502, it is fine..

I also tried to send the SDI out of the 7Q to my older EVF (Alphatron), and then passthrough the SDI out to the 502.. and that works.

Does anyone have a clue why the SDi signal out of the 7Q would be different than the one passing through the Alphatron?
Mitch: is the 7Q processing the SDI signal out in a different way?

Thanks for your help
 
Last edited:
There is an option in the OUTPUTS menu to turn VIDEO PSF OUT from OFF to ON. OFF means that the output is true Progressive, ON means that it is PSF. That should do it as some systems cannot read true Progressive.

BTW, we have this control available because the image quality on the OLED is higher when we use the true Progressive mode.
 
you're probably aware, but is the 502's input select set properly in the settings menu? there is a setting to choose between SDI or HDMI, it's not automatic.
 
Not really sure, but it sounds like it's a SmallHD problem more than a Convergent Design problem. Still, I will ask our engineers to investigate.
 
Thanks Mitch! I also sent an email to SmallHD, and they will also ask their engineers to investigate..
I just find it weird that the two devices seem incompatible.. It's the first time I encounter a device that can't detect the 7Q SDI output signal...
And yet, the Small HD502 can detect all the other SDI signals I sent (directly from the FS700 and from my Blackmagic thunderbolt I/O box)
 
right now i send a 4K signal over HDMI from a GH4 to the 7Q+, and then from the 7Q+ to the 502 over a 25' SDI cable. and that has been working fine for me. we use the 502 as a director's monitor.
 
Oh, now this is interesting: i just tried with a 25' SDi cable (like you) and it works! But when I use Convergent design own 18" SDi cable, it doesn't work...
It also doesn't work with my Cinecoil 20" cable...
Weird.. I never had any problem with those two cables..
Anyway, now I know where the problem is...
 
I've done some further tests, and things are getting even more weird:
- every time I try with a 25' (and longer) SDi cable = it works
- when I try with something shorter (I even tried with a 4inch cable) = it doesn't work..
(I've tried with different brands of SDI cables, at least 10 different cables of different length)

Then, I tried different setups USING THE SAME 6 FEET SDI CABLE
(O7Q is hooked up to FS700 in 4K prores Mode)

- from O7Q > SmallHD 502 = doesn't work
- from O7Q > looping through Marshall monitor > Small HD 502 = it works
- from O7Q > looping through Alphatron EVF > Small HD 502 = it works
- from my Blackmagic thunderbolt I/O > Small HD 502 = it works
- from my Blackmagic thunderbolt I/O > looping through O7Q > Small HD 502 = doesn't work

Then I tried different variations (STILL USING THE SAME 6 FEET SDI CABLE)
- I put FS700 + O7Q in HD mode (not 4k)
- I switch the output on O7Q to PSF (not true progressive)
But always the same result..

When Fs700 is in HD mode, and I hook it to the Small HD 502 WITHOUT the O7Q = it works

So... I don't really know what to think:
- the SmallHD 502 doesn't seem at fault: it accepts all length of SDi cables... except when paired with O7Q, it needs minimum 25' long
- the O7Q doesn't seem at fault: it can send the signal to all brand of monitors... except when paired with SmallHD502, it needs minimum 25' long.

Obviously, I won't be hanging 25 feet of SDI cables on my rig to connect the O7Q to the HD502.. until there's a solution, I guess I'll have to stick to HDMI.. (which I hate though)

ZAK: have you tried using shorter than 25 feet SDI cables? Can you tell me if it works for you?
MITCH: any idea why a shorter than 25 feet SDI cable would cause an issue with 502?
 
and with the 6', did you have any problem?
I also notice that you have the O7Q+, whil I have the O7Q..
 
I don't think the cable length has anything to do with it, I think it's the connectors.

We see this unfortunately often. An SDI connection uses a BNC connector, with the male plug featuring a recessed pin that fits into a sleeve on the female socket. Some cheap off-brand BNC connectors have a center pin connector that is too fat. When mated with a female connector it forces the sleeve to expand. This gives a solid connection for that one cble, and in fact to a very small degree this is how the connection is supposed to happen. But if the male pin is too fat then it will stretch the female sleeve so much that it will remain that way when the male end unplugs. Then when you go to use a proper male connector in this socket the stretched sleeve does not make contact with the pin and the connection doesn't work.

Try a test using our cables, but instead of whichever SDI output you were using, use the other one. The Odyssey7Q+ has an SDI A OUT and an SDI B OUT. Our cables are built with male connectors that are very good and at proper spec. My guess is that it will work just fine. Then you know that the other SDI output on your Odyssey7Q+ has been stretched out by a cheap cable. If necessary, Convergent Design can replace the damaged connector on your Odyssey.

This is why I often say that 80% of our issues come down to bad cables. You'd be surprised at how many ways a cable can be bad.

Please let me know if this fixes the issue for you. I have done similar process of elimination tests for other clients myself, sometimes standing next to them with my own camera and Odyssey so we could trace the problem. It's always the damn cables.
 
OK, so I tried some more tests, using a brand new convergent design cable :
O7Q SDI OUT A > (CD SDI cable) > Small HD 502 : doesn't work
O7Q SDI OUT B > (CD SDI cable) > Small HD 502 : doesn't work

But I tried the same thing with my marshall monitor and Alphatron EVF, and it works.
O7Q SDI OUT A > (CD SDI cable) > Alphatron EVF & Marshall monitor: it works
O7Q SDI OUT B > (CD SDI cable) > Alphatron EVF & Marshall monitor : it works

And when I loop through using that same CD SDI cable , it also works, on either end of the loop:
(O7Q > Other SDI cable > Alphatron > CD SDI cable > Small HD = it works)
(O7Q > CD SDI cable > Alphatron > other SDI cable > Small HD = it works)

And again, when I hook the Small HD directly to the FS700 without the O7Q; it works.
FS700 > CD SDI cable > Small HD = it works

it also works from my computer I/O
(Blackmagic I/O > CD SDI cable > Small HD 502 = it works)

I agree that the length of the cable shouldn't have anything to do with it... it's not logical...and yet, it's the only consistent thing that makes it work in my case..
I don't understand why the O7Q and SmallHD502 can't hook up directly and properly with SDI cables under 25 feet long (take note that only the SDI OUT A works with 25 feet cable.. I've nothing from SDI OUT B)

Anyway, I'm at a point where I've accepted that the only way that I can hook the Small HD502 to my O7Q is the HDMI way...
If I'd known, maybe I could've save myself a couple of hundreds of $ and go for the Small HD 501..

If anyone has any experience with their O7Q (not+) and a SmallHD 502, please share...
 
I'm a bit baffled by it. I've alerted our engineers to this thread but if you would like more proper support, please submit a support ticket via our website or to cdsupport@convergent-design.com.

It should work and it is possible that there is something somewhere out of spec, but I don't know how to determine it without all the gear shipping to our facility for testing. We would need to hook up various analysis devices to check the signals and connections.
 
Thanks for your support Mitch.
I'll submit a ticket.

I'm not saying it is the O7Q's fault, because obviously it works perfectly with every other brands I've come across, but there's definitely going on between my O7Q and the SmallHD 502..
 
Minh said:
Thanks for your support Mitch.
I'll submit a ticket.

I'm not saying it is the O7Q's fault, because obviously it works perfectly with every other brands I've come across, but there's definitely going on between my O7Q and the SmallHD 502..
Click to expand...

Was this problem ever resolved. I've just ordered the 502. I have the fs700 and 7q and hoping no issues.
 
I have an O7Q and a 502 (and FS700). I encountered an issue when trying to send a signal from my BMPCC to the 502, via HDMI, and then send an SDI signal to the O7Q from the 502. The image on the O7Q was distorted and also had an "interlaced" look (the lines). At first I thought that there was something wrong with the 502 but then I tried it with an Atomos recorder/monitor and the image was fine. So the issue seems to be the O7Q and 502 combo.
 
You must log in or register to reply here.
Back
Top