Help My ESL won't make a sound!!!
hon...@my-deja.com
Iv've been working on my first ESL project from materials acquired from
David Lucas.
I've built 2 panels (well actually about 4 but 2 that have the
possibility of working. For those who are familiar with David Lucas
kits I am using Power Bias and his lowest cost transformers.
There is actually a small amount of sound coming from the panels but it
is very faint. I can crank my amp all the way until the protect braker
kicks off with no increase in volume.
Please help, any suggestions would be greatly appreciated.??
Sent via Deja.com http://www.deja.com/
Before you buy.
Barry Waldron
hon...@my-deja.com wrote:
> Iv've been working on my first ESL project from materials acquired
> from David Lucas. I've built 2 panels (well actually about 4 but 2
> that have the possibility of working. For those who are familiar
> with David Lucas kits I am using Power Bias and his lowest cost
> transformers.
Hello,
Diagnosis over the phone line is going to be very difficult; however,
there are some procedures to try and some things to check out.
* Do you have the IMPACT kits, and what stator size did you purchase?
* Did you actually assemble four individual panels or did you construct
two and rebuild them, twice?
* If you rebuilt the panels, did you reuse the tape or use new tape?
> There is actually a small amount of sound coming from the panels but
> it is very faint. I can crank my amp all the way until the protect
> braker kicks off with no increase in volume.
* What make/model amplifier are you using and what is the wattage per
channel?
> Please help, any suggestions would be greatly appreciated.??
The first item to check is the bias supply. Several customers have
complained about not getting them to operate after constructing them,
and/or that they are not reliable. You will need a meter with HV probe
in order to make an accurate test. If you do not have or cannot borrow
these from a technician or ham radio operator, you can buy an electric
fence tester and get a rough indication of the output. If the output
is not between 2KV and at least 3KV then in all likelyhood this is the
source of your trouble.
Assuming that the bias supply and impedance matching transformers are
wired correctly, the next thing to check is the integrity of each
panel. The panels must be mounted in a sturdy frame or easel in order
to insure that they are flat. If a panel is warped or bowed in the
slightest, they will not operate properly. One way to check for
truenes is to place an accurate straight edge (yard stick) against the
panel in several places both horizontally and vertically.
If it is found that the panels are not flat, you can evaluate your
mounting scheme, or better yet, add additional support to the outside
of each stator. This can be done by gluing Plexiglas strips along the
edges of the stator. The actual dimensions are not critical. I used
strips 3/16" wide by 3/8" high.
Once the speakers are playing I recommend checking the movement of the
diaphragms. Under good lighting, with the speakers playing, see if the
entire diaphragm travels freely. If any portion of the diaphragm
touches and/or sticks to a stator, output will be reduced dramatically.
Another thing to check is the integrity of the diaphragm electrical
contact. Try pinching the panel over the area in which the contact has
been placed. It has been reported that if the contact and diaphragm
are not making intimate contact that the panel will not operate. If
this is a source of trouble, sometimes pinching the panel will make the
panel come to life. The fix is to redo the panels! and rub the contact
tape with your fingernail so that its conductiave coating makes better
contact with the diaphragm.
Lastly, although not likely, is the possibility of a high resistance
short between the diaphragm and stator. Two things can cause a short.
The first is a contaminated work area in which the graphite powder
comes into contact with the stator or edges of the support tape. The
second point of contention is if the panels have been rebuilt and care
has not been taken to eliminate any possibility that loose powder
strays onto the support tape causing an electrical bridge between the
two.
These are all possible problem areas. Hopefully you will find that the
power supply is not producing the required voltage.
Please feel free to ask questions and do not hesitate to E-mail me
with the status of your investigations.
Cordially,
Barry
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