Components
Ring Cores for transformers
Ferroxcube (formerly a Philips Components company, now part of the Yageo
Corporation) produce a range of ring cores to the 3C90 Material Grade Specification.
This appears to be an excellent alternative to the '3C85' material (now
discontinued), which was originally popularised for LF power applications by David Bowman
G0MRF. The Philips 3C85 Material Grade Specification (now
archived) provides all the information that you will need about this material.
For a
time, some sizes of the 3C85 ring cores may still available in the UK from Arrow
Electronics (UK) Limited, Edinburgh Way, Harlow, Essex, CM20 2DF. Tel: 01279 626777 (or
+44 1279 626777).
Material |
OD/ID/Height (mm) |
Philips Part Number |
Arrow Stock Number |
3C85 |
25/15/10 |
4330-030-34480 |
058377R |
3C85 |
42/26/12.5 |
4330-030-35520 |
420604R |
3C85 |
58/40/17.5 |
4330-030-35530 |
420605G |
The 25 mm OD core is often used in inter-stage transformers up to 40 W RF. The 58
mm OD core remains cool at 500 W RF, and has been used successfully in PA output
transformers at 1000 W RF.
Another major supplier of Philips ferrite products is Hawnt Electronics, Birmingham,
UK. Tel: 0121 784 2485 (+44 121 784 2485), or Fax: 0121 783 1657 (+44 121 783 1657).
The 3C85 and 3C90 cores are not suitable for use as high power inductors. They
get very hot when used as low pass filter coils in LF transmitters!
Ring Cores for inductors
Micrometals make a range of dust iron cores, including cores suitable for use
in inductors at 136 kHz. Such cores are red in colour and carry a '-2' suffix,
They are available in the UK from: Sycom, PO Box 148, Leatherhead, Surrey,
KT22 9YW
Tel: 01372 372587 Fax: 01372 361421
Part Number |
OD/ID/Height (inches) |
AL Value (uH/100 turns) |
T130-2 |
1.300/0.950/0.437 |
110 |
T200-2 |
2.000/1.250/0.550 |
120 |
The T200-2 core has been used successfully in low pass filters at 100 W RF. An
upper power limit for this component in this application has not yet been determined.
Observations from other experimenters would be appreciated.
High Current Capacitors
Philips Components make a range of '378-series' capacitors suitable for use in
power amplifiers; low pass filters; and for matching LF transmitting loops. These
capacitors are available in the UK from Arrow Electronics (for contact information, see
above).
Value (uF) |
Voltage (Volts) |
Philips Part Number |
Arrow Stock Number |
0.0033 |
2000 |
37892332 |
056343F |
0.0047 |
2000 |
37892472 |
056344D |
0.010 |
2000 |
37892103 |
056345B |
0.015 |
2000 |
37892153 |
056346X |
0.047 |
1600 |
37882473 |
056341X |
0.1 |
1600 |
37882104 |
056342H |
10 m Fibre Glass Pole
The telescopic pole used to support my 12 m experimental vertical is marked:
FIBERGLAS-TELESKOP-TOWER - 10 METER
WALTER SPIETH, DK9SQ, 73061 EBERSBACH, Tel: 0 71 63/59 68
The pole was purchased in England from Sycom (Syon Trading), 16 The Ridgeway,
Fetcham, Leatherhead, Surrey, KT22 9AZ. Tel: 01372 372587 (or +44 1372 372587).
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