I wanted to ask if someone here knows where one could purchase a D whistle that also has a built in drone (relatively inexpensive). I know it takes twice the breath to play one and also wondered if you can disable the drone.
I would like to get one if I could without having to be on a outrageously long waiting list. I remember doing some whistle research on C&F. But I forgot the page where i initially saw it.
Is this close enough to what you are looking for?
http://www.songsea.com/uwc.htm#UILLEANNWHISTLE
$15 and just add it to your existing whistle
Never saw that before, but it’s interesting. The one I am trying to describe looks like a regular whistle except there is second pipe that runs underneath the primary pipe. The air is split down 2 passages 1 for your melody and the other doing a constant D drone.
The ‘read deal’ is this:
http://www.tullberg.com/tully/whistles.html#double
Tony, that’s the one I was looking for thanks. However, is he the only person that makes it?
I have done it before using two whistles, I know everyone here has at least tried playing more than one whistle at a time 
Just of curiousity even.
Here’s another link, this time it’s a DIY (do it yourself)
http://www.ehhs.cmich.edu/~dhavlena/whistle1.htm
Erik the Flutemaker has a double whistle. It’s two Susato Dublins bound together.
http://www.eriktheflutemaker.com/subdetail.cfm?menu_id=581&submenu_id=3345
I believe serpent offers double whistles 
surprised he hasnt chimed in yet actually
um, his website I believe is www.serpentmusic.com
funny you should mention this . . . i was in albuquerque this week and stopped in at my favorite music shop there: Southwest Music, Inc
They had just received a handmade wooden pennywhistle and drone. It played like a dream. The drone was perfectly in tune with the the bell note, d, of the whistle. The wood was beautiful and the sound very soothing. It was a quiet play, but wonderful. The mouthpiece was v shaped and had two small blowholes, one for the drone and the other for the whistle. The entire whistle and drone were made out of one piece of wood. It definitely was hand-made. Cost was $157 and it seemed well worth the bucks. The maker is local in the area who also makes NA flutes.
This was the first one the maker had supplied to the store and I was the first customer to try it. It was not in my budget for this trip, but it is on my wish list. Sweetness.
After reading the DIY drone whistle instructions above, I went home and tried it with my C Sweetone & Meg (both of which I hardly ever play). It took about 5 minutes to find electrical tape and about 30 seconds to tape the whistles up properly.
How does it sound? Well, sort of weird but sort of neat. Pretty easy to play, since double the breath requirements of a Sweetone/Meg are still pretty low. The downside is the way the mouthpieces are shaped makes it hard to get them REALLY close together, so you have to fit your lips over them in an awkward way that causes lots of drooling during playing.
I would recommend doing this just for fun, especially if you (like me) have a lot of cheapie whistles sitting around unplayed. Electrical tape is easily removed if you hate it.