NEQ6 flashing led & resulting bad tracking

[Epicyclus Dave]

Hi all , i just recently built a new "Torness" battery box http://stargazerslou...-diy-power-box/ and have tested it out at remote sites with good results.

On an unusually clear night i had the power running for more than 4 hours , during slewing to another target i noticed the mount power led flashing slowly , i checked the lead & plug at the mount thinking bad contact but that was ok .

Out came my multimeter and i had 12.48V on the battery (13.06V when at full charge) .After noticing the power led flashing i found my images to have trailing stars , small amount but enough for DSS to dislike them .

At home i decided to perform a full load test pluging in one thing at a time and measuring the voltage as well.....

fully charged battery nothing connected = 13.06V.

NEQ6 pluged in = 12.95V.

plugged in 4 Dew heaters on max setting = 12.88V.

Then plugged in the Laptop + 12v charger ( lappy full charged at house) = 12.47V. ahem !!

Ok , the laptop supply is chewing almost half a volt off the battery supply which in turn is setting the mount battery low warning off and possibly affecting tracking too.

I narrowed it down to 2 options .....

A - spend £140 on a go-to handset (i bought the syntrek version with simple control last year) .

B - After searching over the forum i spotted "Merlin" uses a 12v to 15v step up pack £16 Maplin or ebay (they are called universal car chargers 12Vinput / selectable 15V - 19V output 80W )

So i got one of these to feed the mount with 15V even when the battery is at 50% discharge.

Now i just need a clear, cold , starry night to give it a real test , im hopeing this works i seem to iron out one problem then another arises , nevermind, fixing these problems helps you understand all your gear properly

Dave.

[The Sailor]

Have to say that I get that all the time during slewing, now you have mentioned this regarding tracking I will have to have another look at the power, problem is I am using mains power but never looked to see what the power led was doing, eyes elsewhere, thank for that

Jim

[Epicyclus Dave]

Hi Jim , sometimes the supplied skywatcher power lead can cause intermitant contact problems at the socket on the mount , after my warranty has expired i think i will wire direct into the mount using a 16mm compression gland , another 2 months before i can get the power drill out :)

Dave.

[Gina]

For mains power you need a good quality regulated 13.8v bench PSU and substantial enough cabling not to drop the voltage below 12.6v at the mount when everything is working at full power. The Skywatcher mounts will not work off 12v in spite of what the spec says - ex-computer PSUs won't give enough voltage.

[The Sailor]

Might do that Dave, I had a problem with the CG5GT so with the NEQ6 I put the power lead through the "pigtail" of the handset so that it appears I only have one lead to the mount, the power lead is tied off at the top and leaves a loop so there is no strain, have had no problems in that dept. Running through the utility menu on the handset there is an info part that shows temp and voltage, must take a look at that later.

Jim

[Epicyclus Dave]

Hi Gina

So everyone running an EQ mount from a battery should get a step up power pack to boost the voltage for the mount = happy tracking .

The more i learn about all this the more addicted to astro diy i become , heh

Thanks for very interesting info, this forum is great

Dave.

[kookoo_gr]

in my opinion i would suggest buying a battery for the mount alone. the last month i noticed the same thing happening at my mount during guiding using an 80 Ah battery (i had laptop and mount on it) so i bought a 20Ah battery for the mount, maybe a bit of overkill but i can run my mount for about a week before flashing starts. finally i suggest moding your mount and soldering a wire at the mount. The factory one after sometime it will not have good contact and it will cause you issues with power supply. i remember there was a topic at the DIY section where a member replaced the power plug with a screwed microphone jack. here is an example of my mount

[Gina]

Hi Gina

So everyone running an EQ mount from a battery should get a step up power pack to boost the voltage for the mount = happy tracking .

The more i learn about all this the more addicted to astro diy i become , heh

Thanks for very interesting info, this forum is great

Dave.

A "12v" lead acid battery gives 12.6v when nearly discharged - that's at the battery and doesn't allow for volt drop in the cable. Why they didn't design these mounts to run from 10-15v I really don't know. I guess they're alright run directly off a "12v" battery with a short cable with nothing else to drop the voltage. I haven't had much experience running my NEQ6 from battery as I use mains power in a permanent setup. The only time I used battery power was when I first got my mount and used it on it's tripod powered from a car jump starter for a few months (intermittently). I had nothing else running off the supply and my sessions were only an hour or two.

[Gina]

in my opinion i would suggest buying a battery for the mount alone.

I was going to suggest that too.

[Epicyclus Dave]

Good thing about using A.G.M. deep discharge batteries is they can take a better beating than lead acid even in the cold , and my extra long dew strip to lightly warm the battery keeps it at 19C.

My 50% discharge safe level on AGM battery is 12.2V and deceased at 10.8V (never tried that).

I use a RING RSC512 7-stage smart charger to keep the battery sweet.

[Epicyclus Dave]

i'll test the step-up power pack first , i had a 2 battery remote site set up last year but the introduction of the laptop had those 22Ah batteries down in no time , my 90Ah AGM is ideal , i just need to feed the mount with more than 12V as Gina posted , cool .

[philj]

This is a typical sw problem, do a search on here for other discussions, threads on this subject, you will see you are not alone. I replaced the lead with something with a bit more cross section and fitted a proper din connector to the mount as per mine and Demonbarbers mod. Flashing is now a thing of the past

[Tinker1947]

There's a option on my NEQ6 Handset to check the voltage the mount is receiving.......

[Epicyclus Dave]

Yes , good idea , after my warranty runs out i'll do a permenant supply cable into the mount .

Thinking out loud, increasing the voltage to my mount is the best way for my set up , i designed my new battery box for using at remote sites often at -5C & less temp. , employing a second battery for the mount would need to be well insulated as well, but has the same good voltage 'window' of 13V to 12.5V , even less time if it's really frosty.

To keep a one battery 90Ah AGM insulated supply i think have to focus on increasing the volts to the mount.

Thanks for all your great feedback , i'll let you know how the 15v unit gets along .

Dave.

[Kbramley]

I run my EQ6 off a butchered X-box PSU, its has exactly 12V across the terminals at the mount end (8m away), I also have dew heater and mirror fan plugged in to this and the scope appears to track fine all night, however I have noticed the flashing red LED when slewing fast but this is rare event as most of the time its just tracking/guiding. Any ideas why this appears to work? as in theory I guess it shouldn't based on other peoples experiences on this thread.

Cheers

Keith

[Gina]

When slewing, my NEQ6 Pro mount takes 1.1A - tracking 0.6A and not tracking but turned on it takes 0.3A. The extra current taken when slewing will reduce the voltage. In this case to the point where the mount indicates insufficient voltage. When just tracking the lower current means the voltage is above the critical level. Maybe only just though.

[Kbramley]

The only thing I can think of is that I have used a very heavy duty cable (it's like a two core mains cable) thus the voltage drop along the cable is very small. Once I get the obsy set up next year with permanent pier I will be getting a shiny new 13.8v regulated supply .

[pwalsh61]

A variation on the "microphone jack" mod: http://bendun.net/Images/STARFEST2011/EQ6%20Power%20Plug%20Modification.pdf

[tich]

A variation on the "microphone jack" mod: http://bendun.net/Im...odification.pdf

I've done the same mod on mine & it seems to be much better now as I was getting fed up with loosing power then having to do a realignment again. I've just come back from Wales as I was at a Star Party recently & when I did get to use the scope I didn't notice any light flickering when slewing & I was running it via a leisure battery. The power cable I made up is heavier duty than standard & is 20 meters long. I can also remove the Crocodile clips & run it via a 7Amp transformer although I have got a higher amp transformer so I can run the additional dew heaters DSLR etc.

[Epicyclus Dave]

Ha all

I've not had a clear night yet but did get a chance to check the output voltage of the little step up power pack in the pic at the top of this thread , it is providing 15.5v at the 15v setting under load , opened it case up and studied the pcb , quick surface mount component value change and i've now got it outputting 13.8v , yay! .

I set all the gear up inside the garden shed , mount / laptop / 4 dew heaters running off the 90Ah AGM battery full charged to 13v , left it all over night (11hrs) , checked in the morning battery now at 12.18v (at the 50% discharge bracket) and the mount still happily getting 13.8v , no flashing led's even trying a 800x speed slew , looking good so far .

Dave.

[philming]

Hi ! Could you please tell us how you did this last mod ? Maybe some pictures ? Components used ?

Thanx !

[Epicyclus Dave]

Hi Phil

What about just using your power pack at the 15V setting , seems to work fine for a lot of people , i did this because im volt obsessive i'm an electrician through the day and build home made synthesisers at weekends .

If you are interested here is my disclaimer ... then method of attack.

There may be problems sharing my mod .

There are many variations of circuit layout / pcb layouts for these small step up power packs and where i changed a resistor might not be the same remedy applicable to another design.

Cool , that's me free from blame for carbonised / burnt out NEQ6's heheheheh

My power packi bought uses a simple slide switch to select the output voltage (15V ...to...20V) , when i opened the case i noticed the slide switch had a surface mount resistor connected to every pole of the switch , using a magnifiying glass , i saw they had used a small ohmic value (220R i think) for the 20V output , the values rose as the volts dropped , at the 15V setting on the slide switch they had a 820R smd resistor , intuition suggests changing that to a 1K to lower the voltage slightly more , and luckily that for me landed on 13.8V .

Dave.

[pwalsh61]

This topic has been interesting me as I've recently built a "power box" (As per http://stargazerslou...re-battery-box/) with 6 cigar sockets. When I had the scope out on Friday I just had the mount and camera battery adapter plugged in and according to the hand controller the voltage was around 12.3-12.4v. I'd prfer it to be in the 13.5-14v range. I didn't use the laptop (Dell latitude D630) or the car adapter for it (output 19v) as I'd already been reading this topic and am wary of dropping the voltage to the mount. Search around the nearest adapter I could find to that shown at the start of the topic is the UniRoss U0151429: http://www.amazon.co...s/dp/B0017Y01CA so I might get that and (disclaimer noted )give the mod a go. Ideally I'd like to make my own adapter but haven't had much luck at finding a suitable, simple circuit to suit. Anyone got any pointers?

[philming]

Strange that there's no direct 13.5v adapters out there. CB gear (you know, radio things for truckers i.e.) use mostly 13.5v.

[The Sailor]

Just done a search on fleabay using "13.5v power" and got 50+ items, different amps but maybe something there.

Jim