Lowband HF experiments near coastal river delta

Not all hams have similar aspirations of field days. Some go to outdoors for pure fun and relaxation, some to enjoy nature, some to learn about disaster communications using portable setup and some more like us may go in search of low noise heavens!

Many mighty rivers merge to Arabian sea in this region

Hailing from Dakshina Kannada district, I grew up traversing small bridges each day while making trips to school, college and later travelling up the coast from Mangalore till Kundapura etc. The mere scenic beauty of coconut plantations on the banks of these rivers always captivated my imagination. 

After my interest in Ham radio started to grow, I had started dreaming about operating from such locations. As you approach the coast river water draws sea water making it saline. Unlike some backwaters of Kerala, here the water is mostly saline with high PH values except for monsoon season (June - August). Land in these areas are salt soaked and highly conductive. As a ham, tell me if it does not ring your brain hi hi!

Little bit of planning:
In recent years from my Bangalore QTH I had done some decent operations on higher bands. But with Sunspots going down, 40mtr and lower band operation caught my curiosity. But playing with 80mtr and 160mtr from apartment terrace is much less feasible and one would have to be satisfied with the compromises. 

Around the time when VU7T plan was going on with larger team, I wanted to go to a low noise area within VU with single simple objective of having two or three bands to operate at night. When my friend VU3NXI Siddhu got to know of my intention, he caught on to it. I was bit nervous as he was not much on CW and I would go only with CW limited operation. Anyways, I started checking on various websites and zeroed on location based on Google Earth's images and its immediate elevation characteristics. There are many hotels on the coast, but I wanted to go to individual lonely place where they can give entire property access and with no nearby hawkers. I found one small house near river delta point just north of Udupi town. I then had few rounds of information exchange with the owner explaining the purpose of our stay and activities we want to do. Once they got convinced, booked their property on airbnb website.

We applied for temporary QTH change permission for our respective calls. Thanks to WPC, got the permission within 3 weeks without any followups!. Since we had clear objective of low band, we never set goals on QSO counts, but spent time on antennas to be made. N6RK loop (project from VU Contest group) was one antenna for RX and

Terminated RX Delta loop balun 9:1

second antenna I had in mind was terminated delta loop. For verticals we carried 12mtr spider pole and thought of making one vertical and two inverted Ls. The moment I made this field trip news public, many started asking us to carry amplifier and bigger antennas. Come on guys!, this is my first trip to unknown place and that too first experience with low bands. 

I had planned for weekend of ARRL 160mtr contest as some low band operators would have prepared their antennas and winter time propagation advantage on our side. Other than taking down my own station, getting some extra length of coax and some wires cut for 160, 80 and 40 there was not much fancy thing required for us. 

At the location:
Myself and Siddhu reached the place just north of Udupi by overnight bus.  Upon reaching the place we realized that we might be in dreamland as we did not see any HT electrical lines, nor densely populated places in 2-3 kms. We also realized that we should go higher abandoning 12mtr pole to 65-70ft tall coconut trees. We made a quick call to the host and fortunately tree climber was available that day who rushed to our place. 

Our impromptu Antenna setup 3 band trap less full size !

Couple of years ago, i had purchased a large spool of nylon fishing chord from Decathlon store which came much handy. We asked the climber to tie one rope to the tree and drop nylon rope similar to pulley lift. He did the job perfect within 15 minutes. As hams we have to apply all our creative juices to the job done and doing something different and experimenting was exact reason we had this field trip. So we did not pay much attention to whether something should be as per books or no, but we just applied our thoughts. We didn't knew exact height of the tree so we first lifted 80m element and found that around 5 ft of wire would be left after going straight. Pulled that back and now along with 80m (with upper string attached ~5ft lower, we attached 160mtr with center of the wire around 5 feet length away from the main rope. We did not attempt to test SWR yet. We pulled the setup back again and then attached 40mtr element which would hang halfway mark. Few pull up and down we could get symmetry between ropes when we pulled the ends away from center. We then attached homemade choke (mix31 with RG142)at the base of element and pulled elements apart so that it is spaced. For radials we had two for 40, one each for higher bands. Which were run on adjacent to coconut trees at 5-6 feet height. SWR tests showed sharp dips to 1.1 range on all bands near CW region. Aligning the radials would impact SWR with raise in ground loss as we couple of times dropped the radials and saw SWR shooting up above 10. With vertical exercise now completed we went to relish local food at restaurant around 5 kms in nearest town to us.

After lunch we put N6RK loop just around 2ft above ground (next day we raised this to 4 feet above ground and noticed improvement in reception as lot) and delta loop using 12mtr spider pole we had carried. We also had a quick A - B switch done there for playing with loops. 

We were stunned with noise levels. Though I have been to VU4 and VU7, I could not believe signals we were hearing on mainland. Most of the time we just resorted to magical SWLing than CQing!. City

VU2XE and VU3NXI - grey line DX

life had snatched away all our ears and this was really like applying balm soothers. We also found that N6RK loop though having lesser gain, had very low noise and signals appeared clearer. Though signals were very strong on 40mtr, we wanted to make most of our time on 160 and 80mtr. On the first day, I was very tired after long journey and antenna work, so Siddhu operated radio most of time after midnight. Second day, we spent on re adjusting location of the loop to right on the edge of water line and raising delta loop height. That night I also entered lowband chat room as there was good internet available. Each QSO I made on 80mtr had a feeling similar to ATNO!. Hams started asking me to go down to 160mtr after 12:30am IST ( 20UTC). And I did so to realise that good signals come by that time onward. Some NA hams were also getting us well, but I could not hear them.  Keeping watch on morning grey-line approaching fast over the location, I heard a weak K signal. Just seconds away that signal was stronger like 539 -549. It was KA1R the only station we had from NA on 160mtr. He must have studied our google location and was on right time to give us a call. Greyline was so quick that we could not hear any others from NA. 

Boat to cross small hop!

Just after this we dismantled in rush to catch our bus back to Bangalore. Our experiments on the field was most gratifying experience. DXpedition type of goals would not have allowed us to think through, reflect and apply some raw ideas which worked for us in this trip. 

Malpe beach. Launch pad for IOTA  AS - 096 St, Mary's Island

We worked few VU hams such as 
VU2CDP, VU2CPL, VU2ABS and VU2BGS on low bands. We thank them and global top band DXers for being on air/chat rooms with us to help listening, VU3NXI Siddhu for accompanying me and experiencing/sharing joy of the practical aspects of field operation.

Zone vs Band Statistics

So.. what are you thinking now?... Go places! with bit of planning, lot of fun awaiting for sure!

VU2XE
Kiran

Some videos showing our simple antenna setup:

Following is diversity reception audio(use head phone to listen to stereo from 80mtr yagi in one and 1000ft beverage in other) clip shared by VE6WZ. Unfortunately I did not hear him :(