What did the postman bring?

[F15Rules]

32 minutes ago, AdeKing said:

A new to me TAL 100RS in lovely condition with a spotless objective collected from @F15Rules.

For once the sky is clear after receiving a new toy and so it's outside on the Vixen GPD2 cooling down for first light.

 

That looks superb on that Vixen mount Ade!👍

It was great to meet you in person today and have a good natter about all things astro-fracs..

I hope you get your first light tonight and that you are pleased with it😊.

Dave

Edited May 26, 2021 by F15Rules
Typo

[JeremyS]

40 minutes ago, F15Rules said:

That looks superb on that Vixen mount Ade!👍

It was great to meet you in person today and have a good natter about all things astro-fracs..

I hope you get your first light tonight and that you are pleased with it😊.

Dave

Great that you could handle it over to @AdeKing in person, Dave 👍🏻

[AdeKing]

36 minutes ago, F15Rules said:

That looks superb on that Vixen mount Ade!👍

It was great to meet you in person today and have a good natter about all things astro-fracs..

I hope you get your first light tonight and that you are pleased with it😊.

Dave

Thanks Dave,

It was nice to finally meet face to face and have a natter.

My tolerant long suffering wife wasn't quite so tolerant when you were out of earshot though 😳,

It's still clear here so I'm just waiting for the sky to darken a bit before venturing outside.

The TAL sits nicely on the Vixen mount and I'm interested to see how nicely it plays with the iOptron AZPro.

And before you ask @JeremyS the scope didn't have a handle, there was no talk of handles, no Nadira observing chairs were harmed during the scope exchange and there was certainly no mention of Christine Keeler. 😂

[AdeKing]

3 minutes ago, JeremyS said:

Great that you could handle it over to @AdeKing in person, Dave 👍🏻

Damn @JeremyS you're quick.

[F15Rules]

14 minutes ago, AdeKing said:

And before you ask @JeremyS the scope didn't have a handle, there was no talk of handles, no Nadira observing chairs were harmed during the scope exchange and there was certainly no mention of Christine Keeler. 😂

I can confirm Ade's account of our meeting: so, Jeremy, please...no lurid word portraits involving Christine Keeler tied to a Nadira chair (with enlarged seat) being handled inappropriately...😲😱

Thank you very much..

Dave

[Stu]

43 minutes ago, F15Rules said:

no lurid word portraits involving Christine Keeler tied to a Nadira chair

What have I started.....? 😱😱🤪🤪🤣🤣

[AdeKing]

23 minutes ago, Stu said:

What have I started.....? 😱😱🤪🤪🤣🤣

Probably something that will last as long as the handles gags @Stu 😂🤣🤣😂

[Chaz2b]

I thought I’d join the jet set and bought a Telrad reflex sight. But just one question, can I change the two AA batteries for one Li-on battery?, I’ve got lumps of them round the back! I want to make use of them.

Theres even space in there for my sandwiches! Big ain’t it!

chaz

[faulksy]

1 minute ago, Chaz2b said:

I thought I’d join the jet set and bought a Telrad reflex sight. But just one question, can I change the two AA batteries for one Li-on battery?, I’ve got lumps of them round the back! I want to make use of them.

Theres even space in there for my sandwiches! Big ain’t it!

chaz

providing its 3v it should be fine

[wulfrun]

@Chaz2b

One Lithium-ion tends to be 3.7V nominal and 4.2V fully charged. Two AAs only comes to 3V. I think the LED should survive but you might want to avoid turning up to "full", just in case. A voltage regulator would be a better idea but probably overkill and not worth the bother.

Edit: one thing to consider, there's nothing in the Telrad's circuitry to stop you running the cell to "flat", which would ruin it. Best recharge reasonably often or use a protected cell.

Edited May 27, 2021 by wulfrun
added info

[PeterW]

Lithium batteries are light, normally you want some “heft” in your telrad….

Peter

[barbulo]

At least now I have something to read while awaiting for my scope+mount (ordered 2 months ago). 😢

Thks @FLO , you’ve been much faster!

Edited May 27, 2021 by barbulo

[jock1958]

1 hour ago, Chaz2b said:

I thought I’d join the jet set and bought a Telrad reflex sight. But just one question, can I change the two AA batteries for one Li-on battery?, I’ve got lumps of them round the back! I want to make use of them.

Theres even space in there for my sandwiches! Big ain’t it!

chaz

Bought my Telrad over 4 years ago and its still on the original batteries and that’s including leaving it on overnight at least twice. 

Edited May 27, 2021 by jock1958

[Knighty2112]

New addition to the family; an AA Starwave 102mm ED f11 ‘frac. Managed some solar work earlier on, and skies looking good for first light tonight too fingers crossed.

On mount with little brother 80 ed;

Some solar viewing;

Image through scope with quick iphone image taken;

[Chaz2b]

5 hours ago, wulfrun said:

@Chaz2b

One Lithium-ion tends to be 3.7V nominal and 4.2V fully charged. Two AAs only comes to 3V. I think the LED should survive but you might want to avoid turning up to "full", just in case. A voltage regulator would be a better idea but probably overkill and not worth the bother.

Edit: one thing to consider, there's nothing in the Telrad's circuitry to stop you running the cell to "flat", which would ruin it. Best recharge reasonably often or use a protected cell.

None of my li-ons are protected,  I was considering adding a resister, to drop the voltage, but it’s the current that kills, am I right?

chaz

Edited May 27, 2021 by Chaz2b

[johninderby]

Just use a standard Li-on  battery alarm to protect the battery. Cheap enough.

 

Edited May 27, 2021 by johninderby

[Sunshine]

7 hours ago, Chaz2b said:

I thought I’d join the jet set and bought a Telrad reflex sight. But just one question, can I change the two AA batteries for one Li-on battery?, I’ve got lumps of them round the back! I want to make use of them.

Theres even space in there for my sandwiches! Big ain’t it!

chaz

Nice! the Telrad is an unsightly brute who fell from the ugly tree and hit every branch on the way down but, I have always had one as they are reliable as heck and just plain do the job.

[Victor Boesen]

A new flight case arrived this morning. Should be a perfect match for my Evostar 72ED together with some eyepieces and a diagonal.

As a bonus, it also meets the dimensions for carry-on luggage for a small and light setup to bring on vacations

[wulfrun]

10 hours ago, Chaz2b said:

None of my li-ons are protected,  I was considering adding a resister, to drop the voltage, but it’s the current that kills, am I right?

chaz

The simplest solution would be to measure the current on 2x AAs, set to full brightness, then calculate a resistor to drop the excess voltage from a fully-charged Li-ion cell. Then you could also estimate the discharge time, worst-case and know how often to recharge. I have a Telrad, I can take the measurements if it helps...

EDIT: my test-meter says the Telrad draws 21mA at full brightness with new batteries (reading 3.2V). In which case a 47-ohm resistor will drop approximately the required excess 1V. Power dissipation in the resistor is low so you won't need anything exotic. If you're using a typical 18650 cell, you'd drain it in about 100 hours at full brightness. Far longer in typical use, of course. If you have a meter, I'd keep an eye on the cell voltage and recharge at 3.3V, minimum, to avoid damage. HTH.

Edited May 28, 2021 by wulfrun

[HollyHound]

Super fast delivery from @FLO again... only ordered this late Wednesday evening 👍

Unfortunately, I’m in meetings for the next few hours, so won’t get a chance to open it fully until then... so this is just a teaser 🤔

 

Edited May 28, 2021 by HollyHound

[Captain Scarlet]

2 hours ago, wulfrun said:

The simplest solution would be to measure the current on 2x AAs, set to full brightness, then calculate a resistor to drop the excess voltage from a fully-charged Li-ion cell. Then you could also estimate the discharge time, worst-case and know how often to recharge. I have a Telrad, I can take the measurements if it helps...

EDIT: my test-meter says the Telrad draws 21mA at full brightness with new batteries (reading 3.2V). In which case a 47-ohm resistor will drop approximately the required excess 1V. Power dissipation in the resistor is low so you won't need anything exotic. If you're using a typical 18650 cell, you'd drain it in about 100 hours at full brightness. Far longer in typical use, of course. If you have a meter, I'd keep an eye on the cell voltage and recharge at 3.3V, minimum, to avoid damage. HTH.

Presumably you could also use the heat from that resistor to help prevent dewing? Whenever I've used my Telrad dew has been a problem

[Stardaze]

30 minutes ago, HollyHound said:

Super fast delivery from @FLO again... only ordered this late Wednesday evening 👍

Unfortunately, I’m in meetings for the next few hours, so won’t get a chance to open it fully until then... so this is just a teaser 🤔

 

Your postie/DHL/Hermes driver Gary must be the fittest in the country 😆

[wulfrun]

28 minutes ago, Captain Magenta said:

Presumably you could also use the heat from that resistor to help prevent dewing? Whenever I've used my Telrad dew has been a problem

Not really, it's negligible I'm afraid.

[Stardaze]

I’ve spoilt myself twice today. First up, an XW 7 to fill a hole plus a basic camera bag for my EP’s, which I must say, for the money is perfect. Thanks to @faulksyfor the ‘inspired’ idea. 😀

Edited May 28, 2021 by Stardaze

[HollyHound]

15 minutes ago, Stardaze said:

Your postie/DHL/Hermes driver Gary must be the fittest in the country 😆

He’s certainly kept busy 🤣