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Adaptation for 2200m Rx/Tx

Discussion in 'The Low Bands - 630/2200 Meters - VLF' started by WQ2H, Nov 18, 2018.

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  1. WQ2H

    WQ2H QRZ Lifetime Member #214 Life Member Platinum Subscriber QRZ Page

    2200m.jpg

    Moved over from: https://forums.qrz.com/index.php?threads/adaptation-for-2200m-rx-tx.632516/#post-4870030

    First, note typo
    - existing antenna is 160m four wave, not full wave. And thanks to all for all the comments !


    Plan update 18 NOV 2018:

    Transceiver: Motion sensors TVTR2 driven by a Flex 6600M (Motion Sensors suggests that 50W into the loading coil should yield <1W EIRP depending largely on the efficiency of the antenna) The TVTR2 has a Tx inhibitor should carrier frequencies outside the 135.7 - 137.8 kHz band be detected - but I will probably build the 136 kHz pass filter in Dennison's book anyway as it is fairly simple.

    Measurement: WaveNode WN-2 with L/M-1 sensor (100 kHz-5 mHz) on output of transverter. This will augment the graphical SWR meter on the TVTR2.

    Antenna (the long pole in the tent): "Re-purposed" existing 160m 4-wave loop by breaking the feed point at the house, moving one end to a safe distance from the house (~40' to avoid corona), and repositioning the feed point about 30' from the house also.

    Following Dennison's excellent book,(highly recommended) I will also add a 30' vertical segment - essentially making it a 30' vertical with a 2100' hat. The base of the vertical section will be the feed point and will contain a 3 loading coil set (1 variometer, 1 full coil, and 1 multi-tapped full coil) as well as a impedance match box between the coils and the radio. The variometer will have +/- 300uH adjustment in both directions and I will also have several spare discreet 100uH coils available for extra balancing if needed. I will house everything in a weather-proof plastic enclosure at the base of the vertical section. There will be about 40' of coax, and a few surge protectors, between the match box and the radio. I will also need to re-enforce the wire insulator system for spatial isolation at each of the 17 wire "hang points".

    The ground connection is still TBD. I have a very good existing ground farm about 30' back toward the house, or I could build a new ground right at the feed point. I prefer to have it on the existing ground, but we'll see how that plays out.

    N1BUG & K3MF were my first WSPR Rx points on 137 kHz, so I think this antenna with the proper modifications may have a fighting chance.

    Very close to finishing the variometer & coils - so I'll post a photograph when complete. :)
    73
    Jim, WQ2H
     
    KD6RF likes this.
  2. K6CLS

    K6CLS Ham Member QRZ Page

    Yes please!

    You have the right book and great folks helping.

    I haven't set up a TX antenna for the band. But I think for RX my Pixel magloop did very well. Nice to be able to eliminate e plane noise, and steer it away from other noise sources.

    Wishing you every success on the air. And don't set fire to anything!
     
  3. WQ2H

    WQ2H QRZ Lifetime Member #214 Life Member Platinum Subscriber QRZ Page

    Roger on the fire ! (6" of snow on the ground here - but a fire is still a fire)

    I've worked in a HV lab on one of my first jobs out of college so I have an idea of what to look for.

    I'm probably the only ham I know buying corona balls for the screws.......! :eek:

    73
    Jim, WQ2H


     
  4. WB5WPA

    WB5WPA Ham Member QRZ Page

    I don't recall seeing your operation/station working into Europe on 160 ... did you ever have success on that band using that 160 antenna?
     
  5. WQ2H

    WQ2H QRZ Lifetime Member #214 Life Member Platinum Subscriber QRZ Page

    No, not really. The big loop does not seem to work as well as the 8-band Buckmasters on 160 - I have two positioned perpendicular with the long ends W and S.

    The big loop works great within New England, and performs well on 75m also, but it was from day one an experiment. I have a separate smaller 1-wave 80m loop also that I use for phone/digital (mostly Rx).

    This is why I'd like to remove the 1:1 current balun and re-purpose the big one for VLF. It's the only antenna that seems to be able to Rx 2200m (within 350 miles) repeatedly at the moment. I know a "30' vertical with a 2100' hat" sounds goofy, but from what I've heard from other folks it may work fairly well. It's a work in progress.
     
  6. WB5WPA

    WB5WPA Ham Member QRZ Page

    You know, propagation on 160 has really picked up since you last tried it around 11/09 or so (I pulled up the 'spot' records with your callsign). We here in Texas weren't getting many EU spots until the last few weeks even.
     
  7. WQ2H

    WQ2H QRZ Lifetime Member #214 Life Member Platinum Subscriber QRZ Page

    Yes - I have been following your spots. I've been focusing on gathering 2200m data with the couple of stations that I can hear regularly (JT9/FT8). Maybe I will set it up again on 160.

    The variometer is really the big project - found a really nice coffin size waterproof enclosure at Lowes while Christmas shopping. My wife thinks I am nuts of course. Although it is a "nice green color" that will blend in well out in the woods. :rolleyes:



     

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