Amateur radio station since 1993

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LOW BAND DXing ....... direct link : How make 4-directional Flag and Preamp

 

 

 

 

 

 

 

 

 

New GP antenna for 160/80/40/30m

PreAmpAD8129 PreAmpAD8129

 

2018 year ......Modification of the preamplifier and new experiments....................................................................................

9X0T Pile UP on 160m has been received by Quad Direction Flag (+attenuator of TS570)

Signal of 9X0T on 160m has been received by Quad Direction Flag (+attenuator of TS570)

Signal of 3B7A on 160m has been received by Quad Direction Flag (+attenuator of TS570)

Signal of 3C0W on 160m has been received by Quad Direction Flag (+attenuator of TS570)

Signal of TJ2TT in Pile-Up on 160m has been received by Quad Direction Flag (+attenuator of TS570)

 

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

Why Flag ? Why not K9AY ? K9AY or Flag ?

The K9AY antenna doesn't work without ground. It loses the f/b directivity. It needs good ground. Pennant and Flag antennas are ground free antennas. Not problem with good ground ! The Flag and Pennant are much less dependent on the surrounding ground.

The Flag Antenna is in the family of terminated loops that can yield a cardioid (heart-shaped, single-direction null) pick-up pattern. You can direct null of pattern to local source of noise. Switch ortogonal Flags or reversing direction can be rotate the antenna pattern.

The July 2000 issue of QST magazine published an article by Earl W. Cunningham, K6SE, entitled "Flags, Pennants, and Other Ground-Independent Low Band Receiving Antennas". The work presented in the article includes research by several other hams including Jose, EA3VY. The class of antennas discussed comprises single-turn loops terminated on the side opposite the feedpoint. The termination effects a null off the end where the terminator is located, thereby producing a cardioid (heart-shaped) directional pick-up pattern. The antenna is broadband rather than resonant. The pattern produced holds up well over a wide frequency range.

DL2KQ Igor suggested using a reversible flag and gave the idea to use the AD8129 in a preamplifier for a terminated loop (FLAG). Be sure to detuning transmitting antenna - you can switch antennas tuner to other band, better 30 m or 40 m.

1. Kunningham E. W., K6SE. Flags, Pennants and Other Ground-Independent Low-Band Receiving Antennas. QST, July 2000, p. 34—37.

2. Breed G. The K9AY Terminated Loop — A Compact, Directional Receiving Antenna. QST, Sept. 1997, p. 43—46.

PreAmpAD8129

You can download all info about this project as one file

PreAmpAD8129

PreAmpAD8129

PreAmpAD8129

PreAmpAD8129

Block Diagram

PreAmpAD8129

New version Preamplifier with optional filter for 160m band

PreAmpAD8129

PreAmpAD8129

PreAmpAD8129

PreAmpAD8129

Circuit with optoconverter for making PTT voltage

PreAmpAD8129

Second circuit with two power supply (one power supply only for PTT)

PreAmpAD8129

Schematic of connect board for flag

PreAmpAD8129

PreAmpAD8129

New version Injector inside

PreAmpAD8129

PreAmpAD8129

New version PCB (corrected place for transistor)

PreAmpAD8129

 

 

 

Signal of 9Y4/UA4CC on 160m has been received by Quad Direction Flag (attenuator of TS570+DSP NR2)

Signal of TN5R on 160m has been received by Quad Direction Flag

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

Signal of E31A on 160m has been received by Quad Direction Flag (attenuator of TS570)

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 (H x V 4,5x3,5m)

PreAmpAD8129

PreAmpAD8129

 

PreAmpAD8129
8129

 

Preamp

Gain

PCB Preamp

 

 

 

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

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.

 

 

 

160m QSLs has arrived

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