GW4ALG's 136 kHz Pages

[ GW4ALG went QRT in February 2007 ]

Home ] Antennas ] Equipment ] For Sale ] Links ] Logbook ] Introduction ] Station Summary ]

Up ] 100 W P.A. ] 400 W P.A. ] Audio Filter ] [ Components ] Loop ATU ] Noise Canceller ] QRP TX ] Receive Pre-selector ] Remote Controlled Tuner ] SWR Bridge ] Transverter ]


 

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).