Using a SDR as a RFI site survey tool


Twenty Four hours of RFI on 80 Meters

Twenty Four hours of RFI on 80 Meters

This is Part One of a multi part article dealing with setting up a SDR as a RFI site survey tool to assist in RFI detection, location, and mitigation.  Further, part one will set the stage for how captures of the RFI were accomplished, and visualized.  Part one will also  touch upon some of what can be seen and learned from this data.  Methods I used to locate RFI can be found here.  Also some RFI sources signatures have been captured here.

Part two will deal with interpretation of the SDR spectrogram.  Part two can be found here.  Part three will deal with actual location methods, using that portable SDR tool.

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Categories: Cleanup, I have RFI: Series, Info, RFI Mitigation, SDR as Site Survey tool | 1 Comment

Review of the Palstar AT2KD Tuner

AT2KD Tuner, front view

Palstar AT2KD Tuner

This review of the Palstar AT2KD tuner will start off with a few comments about tuners in general, and will not get too technical.  There are many other places to find technical reviews of this device…  eHam ratings indicate that it is a 4.8 out of 5, which is a pretty darn good rating, and some pretty good technical reviews there as well.

Over time I have had both auto tuners, and manual tuners.  I have used differential tuners, and standard tuners…  I always return to manual tuners, using roller inductors, and large caps every time…  An auto tuner is simpler to operate, but the power levels just are not there yet for me on anything I can afford, nor have I been able to get an autotuner, (of the ones I have used), to tune to an exact 1:1, every time, on every band.  It is always something like 1.x:1, I have seen as high as 1.7:1, which can cause issues with the new solid state amps, such as the ALS-1306, which I own.  See the section under “Conclusions”, for more on that subject. Read more »

Categories: Accessories reviews, Info, Palstar AT2KD, Reviews | 4 Comments

Adding an external keypad to the K3

Genovation KeypadThis article on adding an external keypad to the K3 was created to make it simpler for the next poor sod down the road to add a Genovation CP48USBHID, 48 key keypad, or the Genovation CP24USBHID, 24 key device to their K3/P3 devices.  I initially learned about the Genovation keypads on the Elecraft mail list.  It sounded to me like several people were talking as if they had them working, so I asked how to set one up, and got nothing back…  I asked again a few weeks later, only this time on both the Elecraft, and the Yahoo mail lists.  I received several replies, all saying they would like to have one of these working as well.  I did get one lone reply from a person who said, “yes, but I did it a year ago, and have now forgotten how”.  From that I concluded I was on my own in getting these two devices connected.  Given I agreed with the general premise that having a keypad available to send macros to the radio would be good, I decided to move forward with this project and see how far I might get.  I contacted the Elecraft support team first, and got, “only the listed keyboards will work”, response.  However, in the discussion, I got what would later turn out to be a vital piece of information in making the connection between these two devices work. Read more »

Categories: Elecraft K3, Info, K3: External Keypad, Reviews, Setups, Software information, Station | 1 Comment

I have RFI, now what– Locating it

Annotated 40 meters showing various RFI events

Annotated 40 meters showing various RFI events

As the name suggests, this article, “I have RFI, now what– Locating it”, will show how I located several RFI sources in my area.  This is part three of a three part series–  Part one covered what tools I needed to locate RFI, while Part two covered internal removal of RFI sources within the shack, and finally, Part three covers how I located a number of RFI sources external to the shack, and how I got them corrected.  A new section has been added to this site, showing the SDR based signatures of various RFI events, or look over the entire RFI series here.

Over the past few years, I have been plagued with RFI on 40 and 80 Meters.  Most of it has been Horticultural lighting, (read that as Grow Lights), and most of it has been pretty easily located.  In fact most have been found in under 15 minutes!  For the most part the folks I have contacted have all been decent types, and have all to a fault, done what it takes to either remove the RFI, or stop generating it.  For that I am thankful to them, it saves me the time in getting the Federal Communications Commission, and the ARRL involved.  It also saves the person generating the RFI, the problem of federal involvement.  I suspect a lot of this “good luck” has been because I never threaten, or wave the Federal Communications Commission at anyone.  I simply tell them, in writing, what I will do to get the RFI to stop, by giving them a handout the ARRL provides, which approaches the entire issue in a kind, friendly manner.  The goal is to solve the RFI problem at the lowest possible level, not just go straight to the Federal Communications Commission, but to give the person a chance to solve the issue locally, so I don’t have to involve the Federal Communications Commission. Read more »

Categories: ARRL, Direction Finding, DX, I have RFI: Series, Info, Legal Actions, MFJ: MFJ-856, Quantification, Reviews, RFI Mitigation, Setups, Software information, Station, W8VVV: S-meter Lite | 2 Comments

Review of Ameritron’s ALS-1306 Amplifier

Ameritron ALS-1306 Front view

ALS-1306 (Front)

This review of Ameritron’s ALS-1306 was prompted by my selling my older ALS-82 in order to get a no tune amp.  This will not be a technical review, as there are many of those around, and the amp is based on the older designed ALS-1300, with some protection added.

I decided that I wanted an auto tuning amplifier, as opposed to the manual tune, AL-82 I was using.  So I sold the old AL-82, (see my review here), and purchased an Ameritron ALS-1306.   Read more »

Categories: Accessories reviews, Ameritron: ALS-1306, Info, Radios reviews, Reviews, Service reviews, Setups, Station | 7 Comments

Review of “DX World”


DX World Logo

DX World Logo



Several months ago I did a review of “The Daily DX“, and now it is time to do a review of “DX World“.  One is for pay, and one, (DX World), is free.  Yes, free, “DX World” is totally free to the user.  I did not want to do a review without having actually used DX World for a bit, so I started using DX World on a daily basis the day I did the review of Daily DX.

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Categories: DX, DX World, Info, Propagation, Reviews, Service reviews | Leave a comment

Review of Ameritron’s RCS-4 Coax Switch

RCS-4 by Ameritron

RCS-4 by Ameritron

This is a a review of Ameritron’s RCS-4 Coax Switch, covering its use and mounting.  I purchased the RCS-4 several years ago from HRO thinking I would get it outside sometime soon, that didn’t happen.  Two years later it was it was still installed inside the shack, on my feedline, switching between a dummy load, and my feedline run outside.  I recently, decided to add a 4-Square for 30 meters, completely redo my antenna feed system, and replaced my trusty 756 PRO III, with a new Elecraft K3!  This seemed like a good time to really just redo everything in the back yard, and the shack, moving the RCS-4 outside as well.

My GAP Challenger was giving me a bit of trouble anyway, and it was time to rebuild it as it had not been looked at, or touched in a any way, for maybe 10 years or more.  The feedline was getting water in it, and the phasing harness needed replacement, and the three radials needed to be redone from scratch.   Read more »

Categories: Accessories reviews, Ameritron: RCS-4, Info, Reviews, Station | Leave a comment

MixW Telnet DX Cluster Setup

MixW Multimode Software full screen view

MixW Multimode Software

This article will cover MixW Telnet DX Cluster Setup.  MixW is an old, and unsupported program, save for the Yahoo MixW group.  MixW is also the best program I have ever used for RTTY contesting, bar none, and around 4000 other users agree if the membership of the Yahoo MixW support group is any indicator.  I moderate that group, and of late (2014), DX Summit changed it’s format and has broken some functionality of MixW for using DX clusters.  I thought it might be good to put together a guide for how to set up MixW to use Telnet, as opposed to web-based DX cluster population of the cluster selection window.  For some reason many people are not using telnet, but web-based cluster population methods, it seems to me that telnet is much faster, and better, as it relies not on a single site to maintain a set format, for the rest of time, but a set of software packages, (DX Cluster servers), to keep the current formats.  So here is a short tutorial on how to set up MixW for DX Cluster use via telnet.  The steps will be as follows:

  1. Remove all Web-based support.
  2. Modify a script for use.
  3. Add that script
  4. Implement the changes to be automatic on MixW start.

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Categories: Info, MixW Contest Setup, Reviews, Setups, Software information | 1 Comment

Review of the 30 Meter MonoGAP

This review of the 30 Meter Mono GAP, (see my review of the GAP Challenger), was prompted as a first phase for a test bed for constructing a 30 Meter 4-Square phased array.  I also wanted to get a decent antenna for 30 Meters, and I like vertical dipoles because one does not need the huge radial field a  monopole does.  In fact the GAP 30 Mono has only three radials, which aren’t really radials, they are more of a capacity hat for tuning.  The GAP 30 seemed a good selection for a 4 square system, as I would not need to lay out miles of radials, the antenna is small and need no guying, 30 Meters is a fun band, and will be active across Sunspot minimum times, and I have always wanted a vertical phased array.  So I decided to buy one, and test it.  This review is the result of the install.  Look for addendums regarding performance at the end of this article later…  For a closer look at any photo, just click it…  Once you have finished inspecting it, hit the BACK button on your browser.

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Categories: Antenna Reviews, Construction, GAP: MONOGAP 30, Info, Reviews | 4 Comments

NI4L’s 7 Band OCF Dipole

NI4L, 7 band off center fed dipole in the air

NI4L’s 7 band OCF dipole in place

This review of NI4L’s 7 band OCF dipole was prompted by my needing a quick deploy multiband antenna for both field day, and for RVing.  Last year on Field Day I was able to use an OCF dipole for the first time, and I enjoyed the quick bandswitching it allowed, so I thought I’d try and find a good OCF dipole for use while in the field.  After looking around I found NI4L’s site.  Interestingly enough I found it while on eBay, not with Google.  Having looked over his antenna selection I decided on the 7 band OCF version, as that would cover most of my needs while in the field, not need a tuner, and was not too large.  Although I really want a Fan Dipole, (less common mode because the system is inherently balanced up to the coax), for speedy deploy, and the up/down setup/tear down of RVing I decided on the OCF dipole, less wire to play with in getting the antenna up/down.  His web site is very difficult to locate on Google.  Click any image for an very expanded view. Read more »

Categories: Antenna Reviews, Construction, Info, NI4L: 7 Band OCF, Reviews, Station | 5 Comments