Amateur radio station since 1993

RA3WDK `s Homepage

LOW BAND DXing

 

 

 

 

 

 

 

 

2017 year ...... I improved my RX system for winter (2017-2018) season, made Quad Direction Flag with new preamplifier

PreAmpAD8129

PreAmpAD8129

PreAmpAD8129

Signal of 3C1L on 160m has been received by Quad Direction Flag (turn-on attenuator of TS830)

2016 year ...... I improved my RX system for winter (2016-2017) season 160/80 m and use for TX inv L with 10m long spiral vertical part and 26 m long horisontal line. I use pre-amplifier for Bi-Directional Flag 4,5x3,5 m with AD8129 and control switch "Front to Back" only by single RF coaxial cable.

My Bi-Directional Flag 4,5x3,5m

PreAmpAD8129

PreAmpAD8129
8129

 

Preamp

Gain

PCB Preamp

Bi-Directional Flag 3x4 m, look for more info DL2KQ site

BiDiFlag

 

Signal 9M2TO 160m has been received by Bi-Directional Flag

160m filter

Balanced bandpass filter (BBPF) with stable bandwidth from 400 to 900 Ohm for 160 m Bi-Directional Flag and PreAmp

160m filter

Narrow Balanced bandpass filter (BBPF) with stable bandwidth from 400 to 900 Ohm for 160 m Bi-Directional Flag and PreAmp

160m nfilter 

Balanced bandpass filter (BBPF) with stable bandwidth from 400 to 900 Ohm for 80&160 m Band

160m nfilter 

160m nfilter 160m nfilter

 

2014 ......After many years of QRV on VHF and UHF I come back to HF ......

I changed QTH some time ago, but got also high level of noise from neighbourhood. I did not find source of noise - may be modern Led Light, may be remoute control for water tower - I did know. But as result I have noise S9+20 db on 3,5 MHz and S9 on 7 MHz from my GP antenna. Using Magnetic Loop is forced state for this time.

 

RF choke for suppression current in shield of feed from my Magnetic Loop. About 25 db loss on 3,5 Mhz for current on shield of feed to my Magnetic Loop.

RF transformer with separate coil and only connection by magnetic field

Loss and SWR in transformer, look here for 1,8 and 3,5 MHz

Isolation between two coil by capacity with grounded shield of transformer

Isolation between two coil by capacity without grounded shield of transformer

 

160m QSLs has arrived

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