Monthly Archives: March 2017

Update on the Mini-Whip

I had to redo the mini-whip antenna installation as the dowel stick I used ended up folding almost in half. I replaced it with a hardwood dowel of a larger diameter. This is squeezed in between my gutter and roof and secured with a large hammer-in type staple. Pretty sturdy now and up as before about 10 feet.

Photo Mar 29, 12 20 35 PM

20m 1/4 Wave Vertical OTA

I finally setup the 20m 1/4 Wave vertical this morning and started collecting WSPR data. I am run 1/2 Watt WSPR on 20m as NO5V/3 with this antenna. It is really fairly compact as only about 16 feet of mast is needed. I am using 12, 16 foot radials as before and am using the 1:1 current balun I made previously. It is less than 1.5 SWR across the whole 20m band. I’ll run this a couple of days and see what happens. I may try and lengthen this for 40m later this week.

Photo Mar 29, 12 19 59 PMPhoto Mar 29, 12 20 13 PM

My Contest Software Setup

I installed the RA0SMS Mini-whip just in time to use it during the CQ WPX SSB contest this weekend. I use the N1MM Logger+ software during contests. This is a great piece of software with many many features useful in contesting. I am particularly fond of its “memory” and in alerting me to dupes. It connects to my rig via serial port which is ok but it has prevented me from using the panadapter at least until now. I am using a piece of software called VSPE (virtual serial port emulator) that allows multiple applications share the same serial port. In my case my rig is on COM11. The software creates a port called COM21 which can be used with multiple applications. This is useful as the HDSDR software is controlled using Ham Radio Deluxe to control my rig when using it as a panadapter.With this setup I can open HRD and HDSDR as I do during normal HF operations. This gives me the panadapter functionality. Then I can open N1MM Logger plus which links to the radio for frequency information during logging. Her is what the whole thing looks like while running:

Photo Mar 25, 6 41 31 PM

The panadapter display is on top allowing me to see activity across the whole band and select with a click what I want to hear. The contest logger is running at the bottom. Ham radio deluxe is running but minimized as I don’t need its functionality other than rig control. The lower left shows HamCAP propagation prediction tool which is also useful in contests to see what directions I can expect to receive from.

Really happy with the way this worked out! I am a casual contester and generally use the opportunities to evaluate antennas. I made over 70 QSO’s during this contest over 30 prefixes on 40m, 20, 15m and 10m using the end fed vertical antenna.

Installed the RA0SMS Recieve Antenna

Installation of the mini-whip antenna wa straightforward the nice I had all the proper connectors and adapters. I tie wrapped the antenna to a 4 foot length of dowel stick and stuck it between the roof and gutter. It is up about 12 feet. I am using a length of RG-6 TV cable as a feed line to the window feed panel. Inside the shack I have a short length of coax to the bias-t and another to the SDRPlay reciever. Rigged up a power cable to provide the 12V needed to power the antenna through the coax. Did it work?

Well yes! It works quite well actually. It is marginally better than discone on 20m thru 10m and significantly better on 160m thru 40m. I’ll likely try and get some more height outside and clean up the wiring a bit. It is now my dedicated antenna for my panadapter.

The RA0SMS Mini-Whip Antenna

I just received a mini-whip antenna from RA0SMS in Russia.The mini-whip is an active receive antenna that is particularly useful in the low bands. I plan to set this up outside and up as far as I can get it. I’ll use 75Ohm cable TV feed line to bring it in the shack and connect it directly to the SDR play receiver. I have been sharing the discone with my VHF rig and the SDR play so I switch between them when I need the SDR as a panadapter. I am hoping this antenna will work well so I can dedicate it to the panadapter function on HF. The antenna consists of the external antenna and circuitry in a PVC case and a small bias-t box to send 12V up the cable to power it.Here is what it looks like after I unboxed it:


40m JT-65 and the Change to Daylight Savings Time

Early morning hours favor The Western Pacific and Asia on 40m lately. This has been confirmed using WSPR data on the 30 foot end fed vertical. Day light savings time means it stays dark longer in the early morning here at the QTH. I tried 40m JT-65 and it was very active with stations showing up in Japan, Australia, Malaysia, Philippines and China. I did make one contact with a station in the Philippines which was a first for me. The band started dying out about 9am. This looks a great opportunity to work Asia DX even when band conditions are slow (SFI:70 SSN:0). I’ll hopefully try again tomorrow.

Update: 17m is open to Europe in the mid to late morning hours. It is 11am local time here and there is still a lot of activity on JT-65.

Vertical End Fed Antenna on 40m

The vertical end fed antenna using the 9:1 matchbox and 30 feet of wire has looks like a winner on 40m WSPR. It did not make the WSPR challenge board but has shown a respectable 120 unique contacts and a nice spread of DX stations.The mast has held up nicely with a bit of electrical tape at the joints. Here is the 24-hour WSPR map:


Ready to Deploy a 1/4 Wave Vertical on 20m

Now that I have completed the 1:1 current balun I have built a simple wire harness to connect the vertical wire and ground radials for a 1/4 wave 20m vertical. I’ll be starting with 16-1/2 feet of 12 gauge speaker wire and trimming it as necessary to achieve resonance. I’ll use the 12, 16 foot radials I tried before and may add some longer ones before I am done. I was about to go out and set this up but I am still running the end fed wire with he 9:1 matchbox on 20m WSPR and it seems to be doing quite well today. I’ll let it run through 00:00 UTC and see how the WSPR challenge score adds up. I’ll setup the 1/4 Wave vertical sometime tomorrow. I am building this antenna primarily to test against the other combinations and compare to N5CEY’s similar antenna in Los Fresnos. My next step will be to run up the 31 foot wire and use the LDG RT-100 autotuner at it’s base. This mess of wires is the antenna before deployment:


Finished the 1:1 Current Balun

The problem with the balun as I originally constructed seems to be related to contact resistance on the balanced side. I plan to use this on a 1/4 wave vertical so I modified the case to accept a coax connection from the balanced side. It now tests flat SWR across the band. I added a Mega Ohm resistor across the feed point to bleed off any static that may build up on the vertical antenna. Here is what it ended up looking like:



As I have stated before, I am a causal contester. The ARRL DX SSB contest was running this weekend and I used it as an opportunity to test the vertical 31 foot antenna as an end fed with a 9:1 balun with the IC-7100 radio and tuner. I figured this would be good to test on 20m during the day and 40m at night. I didn’t join in until Saturday afternoon and found that nearly all the action was on 15m which tuned up well on the antenna. There was also activity on 10m and 20m. All told I made around 30 contacts using “search and pounce” all of which were DX stations. Sunday morning I tried 40m and made a JA contact, my first on 40m! I was hearing Indonesia as well.

All in all good results of my antenna and rig. This shows that a multiband antenna is very useful to adjust to changing band conditions and that the increased receive sensitivity is being put to good use.

As always, I am shocked to hear so much activity on contest days on bands that one usually thinks are dead. I may start making a point to call CQ on these bands and see if anyone is listening. I may be surprised!