Discovery PDHQ 17.5"

Ratings:Top:Astronomy:Equipment Reviews:Telescope Reviews:Discovery PDHQ 17.5"

 Info  Votes  Messages  More Stats  Up One Level
image
Brand and Model:Discovery PDHQ 17.5"
Price ($USD):$1899.00
Type:Newtonian
Attributes: un-checked Go-To un-checked PEC
Aperture:445mm (17.5")
f Ratio:f/4.1
Focal Length:1829mm
Finder:Telrad
Electric Power:
Mount:Dobsonian
Tripod:
Weight (lbs):175 lbs.
Dimensions (w/h/d):
Description:Price is for a 2" helical focuser and includes a 10mm and a 25mm Plossl eyepieces. The finder is your choice of a Telrad or a 7X50mm Chinese spotter scope. I was able to get mine with no eyepieces and no finder and get a lower price.
The mirror cell is open for ventilation and the tube has adjustable side bearings to make balancing very easy. Discovery also e-mail access and toll-free customer service.
The f/4.1 is no longer available, instead a longer f/5 has replaced it.

Discovery's PDHQ Page

Vote Highlights Vote
Discovery PDHQ 17.5"
Mine is a 17.5 f5 2004 single piece tube, the last year they offered a single piece tube as standard. The optics are excellent as far as seeing conditions have allowed me to judge. The in and out of focus star test images are very similar with the secondary shadow growing to similar sizes at equidistant in and out of focus travel.

The mirror is 2 inches thick. I mounted 3 rear computer fans and 2 smaller boundry layer fans placed in holes cut in the side of the tube. All are powered by a 12 volt deep charge 17 amp hour battery that fits nicely inside the mount. Depending on the rate of ambient temperature drop, cooling can take over 1 hour with the fans running.

At zenith I'm 24 inches off the ground on a step ladder. My height is 5'-10".

The scope arrived with a slightly damaged spider. Each vane had two attach points that were mounted NOT parallel with the tube axis. I replaced it with an Astro systems spider. I have seen pictures of this scope with Astro systems style spiders. You might double check with Discovery so you know what will be used in your scope.

Delivery was about 4 months from order date. By all accounts this was fast. It can take longer. Discovery's estimations of delivery times should be taken with a grain of salt. Be patient. You will eventually have a great scope.

The mount was a little wobbly. I reinforced the side walls with corner braces and extended the front board further up the side walls. This helped somewhat. Basically the mount is a compromise in design. It's center of gravity can not be as low as a truss scope mount and it's weight, with 1 inch plywood sides and 3/4 in bottom, has been held to a reasonable amount.

Motions were a little stiff as delivered. I moved the altitude pads closer together to about 90 degrees and put milk jug washers on the central azimuth bolt. That helped a lot. I use a home made weight to counter a wide range of eyepiece and binoviewer weights.

The scope is big and heavy but with wheelbarrow handles and a garage to store set up the weight and bulk is not an issue. The tube is 88 inches long (I asked Discovery to cut to this dimension. The standard length f5 tube is approx 92 inches.) and it fits snuggly in the Honda Odyssey. Loading is simple and painless with a little in car dolly I made to support the front of the tube and homemade rear tube bracketts for lifting and pushing into the car.


Overall the scope has provided beautiful breathtaking views. It's easy to maintain and cost only 2500 plus 295 shipping in 2004. The cost has since gone up but is still a bargin.

----Big quality optics, simple operation, modificaton friendly and affordable---- Definitely recommended provided you can store set up and have the vehicle to transport.

Overall Rating: 9
Optics:9 Mount:7 Ease of Use:10 Value:10
Weight: 1 (Unreliable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=499740

Discovery PDHQ 17.5"
Recieved the scope with small spots on the primary, but it has no effect on the visual....easy collimation and setup time....sonotube can take a beating.

Overall Rating: 9
Optics:9 Mount:10 Ease of Use:10 Value:10
Weight: 1 (Unreliable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=49784

Discovery PDHQ 17.5"
This scope has a lot of bang for the buck. I will only say one negative thing about Discovery...........Their delivery promises suck.

The 17.5" PDHQ performs, performs, performs. Perfect star test. Easy collimation using a laser collimator. Spiral structure is visible on M51. Bagging a lot of mag 12/13 NGC galaxies.

If you get this scope, slap together two 34" square pieces of 3/4 inch plywood and buy some Home Depot 4" castors so that the scope can be 'portable' at your observing site (my site is my home, and I roll the scope from my garage onto my large driveway). You cannot, I repeat cannot, lift this scope by yourself. It must either be permanently mounted or use the castor method.

I can't say enough about the scope. It is fantastic. The base is not the best, only from a WYSIWYG standpoint,,,, Discovery opted to save about $27 bucks from using nails to strengthen the entire wooden assembly. I drilled some holes and slammed in some 2 inch nails on all surfaces. The base is now solid. I'm not saying it wasn't solid before, but this scope is heavy, and I would like the base to be solid.

The DSC installation is a snap. I just finished putting in mine. Unfortunately, it is cloudy out tonight here in Florida. Anyone wishing to know more about the scope or the performance of the DSC's can contact me at Starman@cfl.rr.com

Oh yeah, I would not purchase the scope cover. I would buy the desert storm cover in the mags.

Clear skies to all,

David

Overall Rating: 8
Weight: 1 (Unreliable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=40602

Discovery PDHQ 17.5"
Good value scope, OK optics

Overall Rating: 7
Weight: 1 (Unreliable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=40601

Discovery PDHQ 17.5"
Rating based on average of 3 categories: mechanics 9; optics 10; value 11.

Mechanics--scope as shipped needed some of the staples holding the teflon pads driven in further as they were grinding on the ebony star formica. Also the inner side-bearings needed some sanding as they were rubbing on the inner walls of the mount. Once these minor adjustments were made the scope moves very smoothly. It is a joy to use.

Optics--I have the feeling of being in a space ship looking out. The moon is incredible, but so are the star clouds in the Milky Way. When viewing Messier objects it is as if I am seeing them for the first time, though I have seen them before in lessor scopes. Images are very bright.

Value--this scope is $1000 less than Discovery's truss tube, and $3000 less than competitor's 18" truss tubes. In my way of thinking this makes it the biggest bang for the buck.

To see my full review of this scope go to www.egroups.com/files/telescopes and click on Equipment Reviews.

Overall Rating: 10
Weight: 1 (Unreliable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=40599

Discovery PDHQ 17.5"
When I received this scope the moirror was cracked! I called Discovery immediately. They replied that I had to wait 6months for another. They where not surprised at my complain. They told me alot of people had complained...

Overall Rating: No Vote
Weight: <none>
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=40600

[Click Here to Login]
Don't have a login? Register!

Checking Your Telescope
Starting out in Amateur Astronomy
 
How to use This Site
Why Register?
[Get rid of the ads!]
Voting Guide