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Posts Made By: Mark Holden

October 4, 2006 10:01 PM Forum: Eyepieces

Best Current Production High Power EP

Posted By Mark Holden
The TMB Supermonocentrics are still in limited production. New, they're only available from Markus Ludes. (an AM sponsor)

They're available in a variety of focal lengths.

Narrow afov, limited eye relief, but sharp and high contrast views. I use them for planets and small dso.


October 5, 2006 05:02 AM Forum: Chinese Optics Imports

Lack of Interest?

Posted By Mark Holden
I think BBs decision to include a 2.5mm planetary eyepiece with the "Planet Hunter" scope is marvelously bad.

I have that eyepiece, and it's a good one.

But 360 power on an 80mm scope is too much for planets on any but the very best nights.

It'll often be fine for globulars, the Moon and doubles but if it's your only eyepiece, it'll be a bugger to aim, and you'll need a very smooth and stable mount.




October 12, 2006 04:54 AM Forum: Refractors

Ed 100 vs premium Apo's

Posted By Mark Holden
itz marcus said:

Hi,
Has anyone done a direct comparison between the Ed 100 and say 4inch Taks, Televues, Stellarvues, WO's TMB's etc? How does the Ed100 hold up on solar system goodies? Are these premium Apo's worth the extra $1000 needed for a used OTA? I'm asking stictly about what reaches the eyeball NOT mechanics , finish, etc..
Thanx

I've done a head to head between a 100ed, the TMB 100/8, and the TMB 115/7.

Your question calls for a subjective answer, and asks people not to consider factors that are part of what makes a premium scope worth buying.

The 100ed is a great "bang for the buck" scope.

Some folks will feel a premium apo is a better deal for their goals. Some will not.

Really, the important question is are you happy with your scope?


October 25, 2006 09:53 PM Forum: Ham and Shortwave Radio

Ham Radio at Star Parties

Posted By Mark Holden
I'm just a short wave listener, but I've been known to bring various radios to star parties. Places that are dark also tend to have little electrical noise.

One year I brought a Racal 6790gm and a Standard Str428 to Stellafane - the forecast wasn't good.

Now, I have an AOR 7030+ that's been customized for camping and vacations. It's in a custom cabinet and It's got two racal crystal filters, two 14.4v sets of nimh battery packs (total of 12 hours listening per charge), an Avantek 30db preamp, and a rapid charger inside.

It out performs all but one of my rack mount receivers. (Nothing I've tried can beat my Harris RF-550)

For an antenna, I normally use a 3 meter govt surplus whip. It's got an impedance matching transformer and attaches with a 1/4-20 thread to a photo tripod. Often as not, the tripod ends up on top of the van I take.


November 5, 2006 03:55 AM Forum: Refractors

Another Comparison - SV4 vs WO 110 ZS

Posted By Mark Holden
I don't think the Zenithstar has a LOMO objective.


November 5, 2006 04:09 PM Forum: APM

3 inch extension with my 175 F8?

Posted By Mark Holden
The TMB scopes are made to be binoviewer friendly.

The classic silver and white CNC models came with a 100mm extension tube. 60 and 30mm extension tubes were options.

Most of the folks I know have 2" Feathertouch focusers in back of the German ones, and we find the 60mm extension gives a nicer range of focus for that setup.


November 7, 2006 12:59 PM Forum: CCD Imaging and Processing/Solar System

Rainout for 11/8 Mercury Transit in CT

Posted By Mark Holden
The next Mercury transits will be 5/9/2016 and 11/11/2019.

The next Venus transit is 6/6/2012.


December 13, 2006 04:58 AM Forum: Ask rating questions here

Seller ethics question

Posted By Mark Holden
I think clarification from Herb would be helpful.

The rules say the rating system is only supposed to be used for completed transactions.

While you did your part to complete the transaction, in the end, the seller completed a transaction with someone else.

Last I knew, there wasn't a loophole for people in your situation. There might be a good reason for it, or it might be this kind of situation hasn't been looked at yet.

Otherwise, getting back to confirm a purchase as soon as possible is a good idea. When I respond to an ad, I'll try to stick around for a while to see if they reply quickly. If they say I can have it, and take Paypal, I'll respond immediately to say I'll be sending payment momentarily. If the seller happens to be near the computer when I first respond to the ad, the whole thing could be wrapped up in under 10 minutes.


December 27, 2006 06:24 PM Forum: Chinese Optics Imports

Planet Hunter Part Two?

Posted By Mark Holden
Tom Davis says he has been using a prototype for it for two years and it uses CaF2 (green laser is invisible in the front element.)


January 9, 2007 02:49 PM Forum: Chinese Optics Imports

Stuff I would like to see made

Posted By Mark Holden
While I think your post was well intentioned, and there is a market for a 6" F8 newtonian, I think the least of Bill's problems is finding good ideas for products to bring to market.

Besides the announced eyepieces people are waiting for, and the 91mm f7.6 scope he's mentioned, he's sitting on several other designs for eyepieces and scopes because he doesn't have enough capital to put them in production yet.

His recent products have been successful, and if this continues, I think his business and reputation will grow. But it won't happen over night.

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