Tag Archives: 160m

Timonium hamfest 2011 and antenna work

Another Timonium hamfest has come and gone.
Buyer turnout seemed pretty good, vendor turnout was slightly thinner than last year, although there seems to have been more tailgating than years past. Most likely due to better weather. I didn’t see too many capital expenses being made although I heard someone talking on the local repeater net saying he sold an entire silent key’s vintage Collins station. Laurie got a chance to use her new HT, which I was sure she really enjoyed keeping up with everyone. No large purchases this year, simple odds and ends and new antennas for our HT’s, but we got a chance to meet up with the 1900 guys from as far out as Pittsburgh and South NJ. Overall another successful hamfest! Can’t wait till next year!

The 1900 Group. Timonium Hamfest 2011

The 1900 Group. Timonium Hamfest 2011

Laurie and I. 2011 Timonium Hamfest.

Laurie and I. 2011 Timonium Hamfest.

The following day, Laurie and I made some adjustments to our 2 meter stack by adding a tilt-over base which allowed me to change the polarity on the cubical quad. Now I can get into N2KEJ’s repeater in South Jersey.

Make shift tilt-over for aluminum military mast

Make shift tilt-over for aluminum military mastNIKON COOLPIX L100 , 4.7, 19.0mm, 0.002 sec, ISO 211

Cubex 2m Cubical Quad and Diamond CP22E vertical

Cubex 2m Cubical Quad and Diamond CP22E verticalNIKON COOLPIX L100 , 4.3, 12.2mm, 0.003 sec, ISO 80

N3QO: 160m mobile

Greetings from a fairly long blog posting hiatus. A few cool things have been in works around N3QO, on or near the top of the list is going 160m mobile. That’s right, 160m.

Barry, KU3X and I discussed the capabilities of 160m mobile in the summer. He had a successful coil design for his mast and whip combination with good signal reports into our nightly 160m net on 1900khz.

Fast forward to this last weekend where I acquired a quick disconnect (QDC) for my screwdriver antenna and a spool of 16ga enameled wire from the LVARC table, all at the Cherryville Hamfest in NJ. Now that I had the wire and QDC, what better time to build the coil and attempt to go mobile on 160m with my High Sierra HS-1500MKII screwdriver antenna.

At first I just winged it, and used a 3 inch PVC as the coil form, with 7 inches of exposed PVC between the end caps. I ended up with a 100 turn inductor that I would later discover calculates to 390uH of inductance. After reviewing someone elses blog about an inductor for this purpose, I ended up being about 110uH of too much inductance. After a little experimenting, I removed about 20 turns and tested again. I had found my resonance was around 5850khz.

This is where I started utilizing my MFJ-259B analyzer beyond the typical SWR readings. I had found a relationship to inductance at the resonant frequency to be 0uH, and 25uH at 1900khz, our target frequency.

With this new information I removed another 5 turns and now found I was around 4:1 SWR at 1900khz with resonance still up and around 5Mhz. It was then I remembered that the 40m shunt coil at the base of my antenna was still in the circuit. Once I removed the matching coil, SWR came down to 2:1. All I had to do now was to raise or lower to the desired resonance, 1:1 at 1900khz.

After I had the test case completed successfully, I re-evaluated the connection points, I decided to drill an entry point to wire the coil from inside the coil, which makes for a cleaner appearance. I also decided to anchor the caps with 4 screws each and not sealing the form in the event of internal coil failure. Because of this, a drain hole exists at the base, only millimeters away from the bottom connection point.

20-Mar-2011 18:23, EASTMAN KODAK COMPANY KODAK Zi8 Pocket Video Camera, 2.8, 6.34mm, 0.006 sec, ISO 50

20-Mar-2011 18:23, EASTMAN KODAK COMPANY KODAK Zi8 Pocket Video Camera, 2.8, 6.34mm, 0.001 sec, ISO 50

20-Mar-2011 18:22, EASTMAN KODAK COMPANY KODAK Zi8 Pocket Video Camera, 2.8, 6.34mm, 0.002 sec, ISO 50

20-Mar-2011 18:23, EASTMAN KODAK COMPANY KODAK Zi8 Pocket Video Camera, 2.8, 6.34mm, 0.001 sec, ISO 50

20-Mar-2011 18:23, EASTMAN KODAK COMPANY KODAK Zi8 Pocket Video Camera, 2.8, 6.34mm, 0.003 sec, ISO 50

20-Mar-2011 18:32, EASTMAN KODAK COMPANY KODAK Zi8 Pocket Video Camera, 2.8, 6.34mm, 0.002 sec, ISO 50

20-Mar-2011 18:32, EASTMAN KODAK COMPANY KODAK Zi8 Pocket Video Camera, 2.8, 6.34mm, 0.002 sec, ISO 50

20-Mar-2011 18:32, EASTMAN KODAK COMPANY KODAK Zi8 Pocket Video Camera, 2.8, 6.34mm, 0.003 sec, ISO 50

20-Mar-2011 18:32, EASTMAN KODAK COMPANY KODAK Zi8 Pocket Video Camera, 2.8, 6.34mm, 0.007 sec, ISO 50

Here are the specs on the coil:
Length not including quick disconnects: 11 inches
Turns: 75 (i think)
Calculated Inductance: estimated 270 uH
Tuning: Allows tuning down to 1815khz at 1:1 with screwdriver fully extended.

On air reports were surprisingly good. I have an Icom 706Mk2 running 100w.
I was S9+20 into Pittsville, MD, S7 into Western PA all from the Pottstown, PA area. This is typical of what I expected, but never that great of a signal.

I’m planning on building another coil with a few less turns with hopes of bringing resonance down to 1800khz even. Then this will truly be a 160m coil.

–jeff
N3QO

2010 year in review

As I’m thinking about what to write about 2011, I’m realizing that 2010 was a pretty kick ass year in the hobby for me and I’m starting to realize I’ve done too much. Here’s a summary.

In February I was introduced to 160m and found a great group located in the PA/NJ/DE/MD area who are on 1900khz every night at 8pm. I would finally get to meet them face to face at the Timonium Hamfest in Maryland which would start an every other Saturday tradition of breakfast in Delaware with the guys.

The hexbeam I built back in the previous October (2009) survived the 2ft of snow we saw in March. I would find myself being invited to operate the ARRL DX contest at NE3F’s, which is always fun but also quite an endurance run. I also started operating HF mobile and ended up working VK7ZE on our way to our club station with 100w in a screwdriver antenna on 20m. He was working the states long-path, some 14k miles.

Early in April, I decided to try a 3 element Mosley TA-33 tribander and ended up selling my Hexbeam to Dave (K3GMT). Also in April, I went QRO with a Dentron Clipperton which would be a requirement for 160m in the summer. 1200watts with a set of 4 572B’s. The transformer makes a menacing growl when it’s cranked on 40m, truely a welcomed addition to the shack.

Early in May, Jon (N3INJ) called to tell me 6m was open, of which I didn’t have an antenna for. Within about 45 minutes, I had a 6m delta loop up in the air and started making first 6m contacts. Later that month Laurie and I made it to Dayton. This was our first and plan to make it a yearly event.

I started off the month of June by rotating the polarity of my 2m cubical quad to horizontal and start working 2m sideband. So far it’s been slow, but my furthest stations I’ve worked was Pittsburgh and Connecticut, but the ARRL VHF contest was a blast!

The 1900 guys and I would end up doing a Field Day Expedition to Assateague Island in Maryland. It took a fair bit of planning, governmental politics and a little bit of cash, but we pulled it off. We also pulled off toasting an Alpha amplifier and an Icom 7000. But we all made it out alive with a new experience under our belts and I experienced a pileup the night before on PSK from the beach.

Early in July, I installed the trapped 40/80/160 antenna and start getting S9+40-50 signal reports on 160m, something no G5RV would do. Later that month I would end up in,out and then back in the hospital for a perforated appendix, which made for good rest time for DX at home, but no HT’s in the hospital. I also missed out on IoTA weekend, bummer.

In August I started playing around with satellites and sold the Icom 746 and purchased a Yaesu 847. Just as quickly as I got into this mode, I was out of it, but I walked away with a QSO with Commander Doug Wheelock aboard the ISS while we were mobile.

September my HF configuration came full circle. I ended swapping out the Mosley for my previously rebuilt hexbeam. Luckily for me, K3GMT’s plans for it didn’t work out, and I have my creation back on the roof and working DX like a mad man. At the same time we relocated the 2 meter antennas to a newly installed guyed mast just behind the garage.

October 1st I would wake to find my shack in the basement flooded due to a large rainfall. A normally quiet sump pump would awaken in the night, but a tripped GFI breaker caused it to stop and leave me with a foot of water. No ham equipment was harmed, but the shack ended up being relocated to the dining room. Luckily for me I have a loving, understanding and licensed (general) YL. Speaking of which She and I worked the PA QSO party, but she has not yet given up my Icom 706. I don’t have the heart to take it back, and not that I need it, but it gives me an excuse to buy another rig.

The last quarter of 2010 has been fairly quiet. I’ve been voted into the board for my radio club, working towards DXCC, working more CW and playing around with APRS.

Laurie and I are both looking forward to a prosperous 2011, with me hopefully working HF mobile once again. Hi Hi.