Home
Circles
Gallery
Systems
Calendar
About/Help
Login
Register
Circles
»
Other Stuff
»
Archived Manufacturer Circles
»
Hagerman Technology
(Moderator:
hagtech
) »
Topic:
Cornet Questions
« previous
next »
Print
Pages: [
1
]
Go Down
Cornet Questions
0 Members and 1 Guest are viewing this topic. Read 1848 times.
smbrown
Jr. Member
Posts: 59
»
Gallery
Cornet Questions
«
on:
8 Mar 2005, 11:32 pm »
Just got my blank circuit board a couple days ago and been stuffing since then.
Got a couple questions - first off, the resistors spec'ed from Mouser are metal oxide, I didn't pay attention to this until after I ordered them. My past experience has been in favor of metal film over metal oxide - anyone had similar experiece?
Secondly, on the website it says the board comes with instructions including decals. I thought, gee, that's great it will make a professional looking finish. However I don't see any decals in mine, but I do have some printed pages of panel labels. Are these the decals? I guess I was thinking more like a peel and stick or something (remember building model planes as a kid?). At any rate, if this is it, does someone on the forum have an idea for making a peel and stick or heat transfer application? I'm thinking there must be something clever I can do with transparency film in my ink jet printer? In addition, since I'm putting mine in a black chassis, anyone have a clever idea of how to make the black lettering white and make it stick to the chassis? Thanks!
Overall I'd say I'm very impressed with the quality of the board, can't wait to see what it sounds like. Oh, one last question - on the power transformer, I know the Hammond is a 50ma unit, but what is really needed for the kit? Is it 50, or 20 or? Makes a difference in that I might be able to use a surplus small tfr from an old heathkit signal generator rather than the Hammonds (I don't like that knockout that shows). I know, picky picky...
Thanks all!!
Logged
Eric H
Jr. Member
Posts: 67
Cornet Questions
«
Reply #1 on:
9 Mar 2005, 01:05 am »
yeah, those are the "decals"... decal to me always meant the kind where you soak them in water and transfer them off like I used on plastic models as a kid. I'd like to have some of those for my Cornet.
I used the metal films and I have no complaints, never done a comparison.
You should be able to figure out the current draw from the schematic, I think, and tube specs... realize there was some issue with a smaller transformer in the early cornets so Jim spec'd a bigger one. Mine barely even gets warm, not even close to hot.
You'll love your Cornet... what chassis are you using?
Logged
smbrown
Jr. Member
Posts: 59
»
Gallery
Cornet Questions
«
Reply #2 on:
9 Mar 2005, 02:16 am »
Thanks for the response. I am still debating on the chassis. I have a Hammond black powder coat, but I keep thinking about maybe making this a full preamp, not just a phono stage. I suspect I'll do it as a stand alone phono just to give me some versitility.
Logged
Eric H
Jr. Member
Posts: 67
Cornet Questions
«
Reply #3 on:
9 Mar 2005, 05:10 am »
Check the archives - Jim built a Cornet+Clarinet in one chassis a while back... I believe he used only one transformer.
The Hammond chassis take some effort to make work - check the archive about that, too... but I'm very happy with mine now that the work is over. I used black hammered-type paint and posted some not-so-great pics a while back... The 12x8x2 chassis in particular is very tight, I gave up and used 12x8x3 but another guy here did the 12x8x2 successfully...
Logged
hagtech
Facilitator
Posts: 2269
»
Gallery
Cornet Questions
«
Reply #4 on:
9 Mar 2005, 06:02 am »
Smbrown,
Did you not get adhesive-backed laser label (ok, I called them decals) with the board? Backing should peel off. It's not the prettiest label in the world, but it works. Actually not too bad when used with a light coat of lacquer (too heavy discolors the label).
For Cornet2 you don't really need labels, everything should be obvious. Inputs on left, output on right, viewed from front. Decals are mainly for Clarinet where the controls needed names.
Circuit only uses about 20mA from B+. But be careful when swapping power transformers. The internal resistance of the secondary winding is taken into consideration for proper output voltages. That is, at only 20mA, the secondary puts out a bit more voltage that if loaded down to full spec. All of the resistors in the power supply circuit have been sized for this particular transformer. Swapping is ok, just be ready to change a few resistor values. Also, the 6V winding should be rated for twice the required dc current (losses in rectification).
jh
Logged
smbrown
Jr. Member
Posts: 59
»
Gallery
Cornet Questions
«
Reply #5 on:
9 Mar 2005, 11:44 am »
Thanks for the reply, Jim. No, no peel and stick lables.
On the transformer, I think my surplus unit will work okay, I'm using a similar one right now to provide 340v to a preamp that uses 2x 5687's at 10mils each + RCA Phono and it has run fine for the last couple of years. So I'll go ahead and give her a try. Only problem is that there is no 5v winding (Heath used a 6x4) so I will have to add a small filiment tfr under the hood.
I understand the note about changing some resistors, the two 6.8k's will need to be changed. I was almost thinking of substituting a couple of chokes mounted off board instead of the resistors since my tfr secondary is a bit lower than the Hammond. Any point in putting a choke in there, or is it over kill?
Thanks!
Logged
hagtech
Facilitator
Posts: 2269
»
Gallery
Cornet Questions
«
Reply #6 on:
10 Mar 2005, 03:37 am »
Shucks, I'll send you the decals right away. I must not have had my coffee yet...
You could use chokes. I think this was done by gurevise or someone else. I like chokes.
jh
Logged
bluesky
Full Member
Posts: 374
Cornet Questions
«
Reply #7 on:
11 Mar 2005, 05:57 pm »
Hi Everyone
There are a few solutions to the problem of decals that I know of which I will be following up for myself.
There are lots of sign writers and label making companies who use a PC based program to produce the decals that we are familar with. That is, the clear plastic with the lettering of your choice and the Hagtech logo. There is a place nearby me and I will go to them on Monday to ask more about this and the costs involved.
Another option are badge makers. I do some part time work at my local primary school and you are given a badge to wear whilst working. It has a clear overlay and whatever design you want on the base level. It looks quite good and could be a pretty classy self adhesive badge with the Hagtech logo. Again, I will try to follow this up after the weekend.
There is the option of trying to do it yourself on your own PC. I don't know how to do this but will ask my son and his mates at high schol who know much more about computers than I do.
Lastly you could just go to your local mall where there always seems to a shop that does engraving by hand of everything from dog collars to watches and jewellry with a little engraving tool. You know the guys who just pick it up and write perfect lettering on the metal thingmabob you have. Like my dog's collar with "Misty" and my contact phone number for when she does a runner when a gate is left open.
Cheers
Ian
Logged
Print
Pages: [
1
]
Go Up
« previous
next »
Circles
»
Other Stuff
»
Archived Manufacturer Circles
»
Hagerman Technology
(Moderator:
hagtech
) »
Topic:
Cornet Questions