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630 Meter Instructional Topics

A few tips that might improve your MF and LF listening experience at Field Day

– Posted in: 630 Meter Instructional Topics, 630 Meters

The MF and LF Field Day demonstration and outreach opportunity that has occurred for several years now is intended to expose operators to new spectrum while utilizing existing field day stations and equipment.  Many operators today still have no or little idea about what is capable on these bands while others dismiss these bands altogether [...]

Trying to figure out how to measure the EIRP of your short vertical antenna? Here’s how I do it!

– Posted in: 630 Meter Instructional Topics, 630 Meters

THIS PAGE IS UPDATED FREQUENTLY AS PROCEDURES ARE IMPROVED AND CALCULATIONS ARE REVISED SO PLEASE CHECK BACK OFTEN! Radiated power can be tough because there is so little calibrated equipment that is readily in the possession of the average amateur.  Making useful measurements rounds out the problem.  Here is how I make measurements of my [...]

Simple Remote Antenna Current Meter By Rick W7RNB / WI2XJQ

– Posted in: 630 Meter Instructional Topics, 630 Meters

Simple Remote Antenna Current Meter By Rick W7RNB November 20, 2016 Using an RMS, thermistor current meter at the antenna coupler was my first line of defense. However after reading Ralph's (W5GJV) article about a remote current sensor and meter in the radio room seemed very appealing and smart with the rainy Northwest weather. Also [...]

Minimizing the Dreaded Drift of MF or LF October, 2016 by Rick W7RNB / WI2XJQ

– Posted in: 630 Meter Instructional Topics, 630 Meters

Minimizing the Dreaded Drift of MF or LF October, 2016 by Rick W7RNB / WI2XJQ Drift – That is frequency drift of your transmitted signal on either the LF or MF bands. It happens, whenever your running a transmitting downconverter. There always the possibility that you will drift a few cycles. The experience encountered was [...]

A look into radios that are WSPR and JT-x friendly – By Rick W7RNB / WI2XJQ

– Posted in: 630 Meter Instructional Topics, 630 Meters

A look into radios that are WSPR and JT-x friendly By Rick W7RNB / WI2XJQ This article is somewhat timeless because the radios that are available today that will provide WSPR and JT-x compatibility fit into two catagories. Above $1000.00 and below $1000.00. For this exploration I chose to go with the lesser cost radios [...]

ICOM IC-735 as a Receiver for WSPR on 630 meters – By Rick, W7RNB / WI2XJQ

– Posted in: 630 Meter Instructional Topics, 630 Meters

Below, Rick, W7RNB / WI2XJQ, explores some of the challenges and resolutions he had while using an older amateur receiver on 630-meters with modes requiring high accuracy and precision with respect to frequency. At the beginning of my journey on 630 meters I did a lot of reading about different topics about the 630 meter [...]

Getting started on 630-meters: A quick means of evaluating your receive capabilities using WSPR

– Posted in: 630 Meter Instructional Topics, 630 Meters

Many operators stumble on to 630-meters by accident, having had no intention of embarking on this crazy journey when they began.  Often times the first experience for many operators is through WSPR, the Weak Signal Propagation Reporter developed by Dr. Joe Taylor, K1JT.  It is an excellent tool for evaluating band conditions for possible QSO's [...]

Why we like to stay away from stainless steel hardware in RF applications

– Posted in: 630 Meter Instructional Topics, 630 Meters

Laurence, KL7L / WE2XPQ, sent this picture of his 2200-meter loop coupler after his WSPR-15 session last night: Laurence indicates the following in a post of the European LF reflector: "The Stainless 5/16th bolt in the feedthru must have had some imperfections in manufacture and got extremely hot at circa 50-60A :-) it didnt happen [...]

“I want to build a new transmit antenna but how do I know how much power I need to make the EIRP limit?”

– Posted in: 630 Meter Instructional Topics, 630 Meters

UPDATE March 28, 2017: Do you have a quality antenna analyzer and are you using a base loaded vertical?  Continue reading but also check out this link for the steps that I use to make measurements useful in determining EIRP. ...That's a very good question and one that is difficult to answer.  Theoretically the best [...]

The ON4KST “kHz” logger / chat: a game changing tool in the pursuit of MF and LF QSO’s

– Posted in: 630 Meter Instructional Topics, 630 Meters

In the summer of 2014, the stalwart group of medium wave and long wave operators was looking for a means of real time communications for scheduling QSO's, sharing band condition information, and having technical dialogues.  There are a variety of email reflectors that could accommodate this but sometimes there is latency, with emails not being [...]

The In’s and Out’s of Filing an Application for a Part 5 Experimental license on 630-meters

– Posted in: 630 Meter Instructional Topics, 630 Meters

September 16, 2015 UPDATE:  The FCC appears to be content with grants in the 465-490 kHz range at up to 10w ERP at this time. Always research current, existing grants before filing applications to ensure that you are getting the best deal.  This thing is very fluid at the moment and what is allowed can [...]

Implementing an effective ATU for 630 meters

– Posted in: 630 Meter Instructional Topics, 630 Meters
Low voltage relay mounted on the fiberglass pole

John Langridge KB5NJD / WG2XIQ (Originally written in August 2012) Up until this point, I have detailed the construction of a loading coil with variometer, effective CW transmitters for 630 meters, and modifications to an MFJ antenna analyzer in order to make reasonably accurate measurements at these frequencies. Truthfully, that was the easy part. Implementing [...]

A 630-meter transmit down-converter utilizing transistor mixing plus a 10-watt Class D power amplifier for little $

– Posted in: 630 Meter Instructional Topics, 630 Meters

John Langridge KB5NJD / WG2XIQ (Originally written in September 2012) UPDATE August 9, 2015:  If you are building one of these transmitters, note that in most cases the low pass filter is not good enough for the 50 db harmonic suppression that is required by the FCC in the US.  I hope to do a [...]