:On Tue, 5 May 2009 07:02:25 -0700 (PDT),
[email protected] wrote:
:
:>> On Mon, 4 May 2009 09:49:51 -0700 (PDT),
[email protected] wrote:
:>>
:>> :We're trying to find a replacement ferrite pot core. The core is just
:>> :like the type shown in this picture:
:>> :
http://www.electronicsurplus.com/objects/catalog/product/image/img700...
:>> :It measures .439" in diameter, each half measures .130" tall.
:>> :Also, it is marked 3B7.
:>> :
:>> :I haven't been able to find any this small.
:>> :We only need small quantity, 1-5.
:>> :Any ideas?
:>> :
:>> :Thanks,
:>> :Steve
:>>
:>> Most likely a P11/7 with a zero air gap. If both halves are identical to the
one
:>> on the right then it will be most likely be ungapped. If gapped, one half
should
:>> have a threaded insert to take an adjuster slug.
:>>
:>> The current Ferroxcube data sheet doesn't include 3B7 material since this is
:>> obsolete. In 2003 they recommended 3H3 as its replacement, but as you will
see
:>> from the data sheet 3H3 is also superseded. You should still be able to get
them
:>> though.
:>>
:>>
http://www.ferroxcube.com/prod/assets/p117.pdf
:>
:>Thanks for the great replies. Neither side has threads, there was no
:>adjuster slug. The dimentions add up, it does indeed look like a
:>P11/7-3H3 will work.
:>
:>Thanks,
:>Steve
:
:Gapped parts often have labelling that refers to the intended AL value
f an assembly. If just the material is marked, the part likely has no
:gap.
:
:RL
It is very easy to determine gapped cores simply by aligning the two halves and
holding them up to the light so you can see through the side slots. The gap in
the centre leg of the core is quite noticeable. The P11/7 3B7 cores I have made
by Philips pre 1990 have a threaded nickel plated insert in one half to allow
for the adjusting slug to vary the final inductance value. The zero gap variety
doesn't have the insert.
