Parts and tools used:

DXE-6UQ-CTL – Quad Shield 75 ohm Coaxial Cable
CNL-911 – Channellock Cable Cutting Pliers
DXE-CPT-659 – Coax Cable Stripper
DXE-SNS1P6QS-10 – Watertight Snap-N-Seal® Coaxial Connectors (10 per package)
DXE-SNS-CT1 – Compression Tool for Snap-N-Seal® connectors
Xacto style knife

A. Cut the DXE-6UQ-CTL F6 size Quad Shield cable square to the end. Use a CNL-911 cable cutter rather than diagonal cutters, which can compress the coax cable too tight when cutting.


B. Using the CNL-911 Cable Cutter, round the end of the coax cable.

quadshield-2  quadshield-3

C. Using the DXE-CPT-659 Coax Cable Stripper, prep the quad shield coaxial cable. Following the instructions for the tool, place the quad coax cable into the tool with the end flush to the tab. While holding the coaxial cable, rotate the tool around the coax about 5-10 times. When the cutting is complete, you will feel it move more freely. Remove the tool, pull the two parts off of the ends.


Per the specifications for the Snap-N-Seal connectors, the DXE-CPT-659 Coax Stripper Tool will make two cuts on the quad shield cable. 1/4” of center conductor and 1/4” of the coaxial cable jacket will be removed exposing the braid & foil shield.

quadshield-5 quadshield-6


Note: Some people like to have a longer center conductor. The DXE-CPT-659 can be modified by removing the small stop tab, which allows you to insert more coaxial cable, which will result in a longer exposed center conductor.


D. Fold back the outer braided shield onto the black outer jacket (a small stiff bristle brush works good for combing the braid back) as shown. Carefully remove the first layer of foil to expose the second braided shield. Once this foil is removed, fold the braided shield onto the outer jacket as shown. You can leave the bottom layer of foil, or remove it to ensure nothing will migrate and short out the connector.

quadshield-9 quadshield-10 quadshield-11

E. Insert the trimmed coaxial cable into the DXE-SNS1P6QS Snap-N-Seal® connector. Pushing in the cable while having the connector braced against a stop helps while you push in the cable. Push until the center insulation is flush to the inside lip looking in the end of the connector.

quadshield-12 quadshield-13 quadshield-14 quadshield-15

Note, if you modified the DXE-CPT-659 cutter to allow a longer center conductor being exposed, you will have to ensure that when pushing the cable into the connector, you do not bend the center conductor when you are pushing against a brace. (Just a suggestion: Use a 2” x 4” piece of wood with a small hole drilled that will fit the center conductor and place the connector over that hole while pushing on the cable).

6. Fully seat the coax cable with connector into the DXE-SNS-CT1 – Snap-N-Seal Compression Tool and squeeze the handles completely so the tool completely seats the compression ring end into the connector body.

quadshield-16 quadshield-17 quadshield-18 quadshield-19

7. Remove the cable from the compression tool. Done.


When assembling any aluminum tubing sections together you should take the following steps:

1. Make sure the edges are smooth and not sharp. Deburring may be necessary, since burrs and shavings can occur on seams as well as edges. All surfaces need to be completely smooth to allow easy assembly of tubing sections. DX Engineering’s aluminum tubing adheres to the stated specs closely so even the theoretical clearance between sections is very small. On the order of 4-thousandths of an inch total clearance (2 thousandths on the radius), it won’t take much dirt to cause a jam when the next size tube is inserted.

aluminum tubing edges can be very sharp

The raised particles and shavings that appear when the aluminum tubing is machined are referred to as burrs, and the process by which they are removed is known as deburring.

Deburring is a finishing method used in manufacturing. Our aluminum tubing is machine-cut on both ends. The slit tubing is also machine slit on one end. You should further assure that there are no ragged edges, burrs or protrusions.

DX Engineering Tube Deburring Tools DXE-UT-KIT-DBRDX Engineering recommends the DXE-UT-KIT-DBR Tube Deburring Tools, or the DXE-22600 Deburring Tool with Extending Handle and Extra Blades for this operation.

2. Clean the outside of the aluminum tubing to clear any dirt or foreign material that would cause the clamps to malfunction during assembly.

3. Clean the inside of the aluminum tubing to clear out any dirt or foreign material that would cause the aluminum tubing sections to bind during assembly. Do not use any type of oil or general lubricant between the aluminum tubing sections. Oils or general lubricants can cause poor electrical connections for radio frequencies. The use of JTL-12555 Jet-Lube™ SS-30 is highly recommended. SS-30 is an electrical joint compound which affects a substantial electrical connection between metal parts such as aluminum tubing or other antenna pieces. Using SS-30 assures high conductivity at all voltage levels by displacing moisture and preventing corrosion or oxidation.

4. When assembling the aluminum tubing sections, ensure the area is clear of grass, dirt or other foreign material that could cause problems during assembly of the closely fitted aluminum sections.

Stainless Steel Element Clamps (DXE-ECL Series) are available from DX Engineering. Slide all the DXE-ECL element clamps over each aluminum tubing section as needed before putting the tubing sections together. You can lightly tighten the element clamps just below the slits on each of the aluminum tubing sections to hold them until needed.

Element clamp on aluminum tubeAlign the element clamp screws on each aluminum tube section to face the same direction. At final assembly, the body of the element clamp should be positioned between the slits in the aluminum tube and approximately 1/8″ from the edge of the aluminum tube, as shown.

Many homeowner associations (HOAs) frown on ham radio antennas. So dedicated hams are forced to get creative, often turning landmarks into operable antennas.

John did just that, and shared his project with us this week.

John lives in The Villages, Florida, where more than 350 other hams reside, and 227 are members of the K4VRC ham radio club. He recently completed a custom-built antenna/flagpole project with the help of DX Engineering, and mailed us the following pictures and descriptions of the project.

John included a note that reads: “Tim, K3LR + Mark, W8BBQ: Thanks for time taken to answer my ‘many one last questions.’ Pictures are worth a thousand words and so is DX Engineering!”


“The beginning! This pipe accepts smaller pipe on antenna. When I got my ground rod driven down about 6 foot I could push the remaining 2 feet down with my foot! No wonder Florida has so many sink holes!”


“By using long galvanized pipe can tie everything together for added strength! Plus just stand entire unit up and slide pipe into mating pipe cemented in ground. Used small bolt through both pipes so flag pole can’t turn.”


“Used gray puc (sched 40) – just right size to cut into base of antenna. Used special shims on other side so 3 SS straps tightened up make everything as one.”


“Just another angle. Is this going to work?? How will it look?”


“Beginning to get better feeling as everything might be OK!”


“Continuing higher and ‘thinking ahead,’ or trying.”


“Fabricate as I go. No glue. SS screws. Slits in top pieces so rods slide through.”


“Each section SS screws. No glue. Rods attached. Then cut slits in top piece, which slides down and then screwed.”


“I pledge allegiance. – – – – cq – cq – cq – cq 20 – cq 20 – cq 20. I am very pleased!!! Thanks for guidance.”


“Closer look at top. Gold top has air vents so humidity + heat can rise but no rain can enter. Also note: each section not glued. SS screws. I can get to all sections of antenna. Grooves (slits) cut for rods.”


“Pretty much what finished project looks like. Flag is not at half mast, but as high as I was comfortable with flag so wouldn’t hang up in rods!”


“Large diam. green PVC covers up everything at base with smaller PVC brought out for solar flag light.”


“Weather tight box with lightning arrester inside. Here I drove two 4-foot ground rods down and solid all the way! Phew! I brought ground up through bottom of box for lightning arrester and main ground continues to inside.”

It’s Time to Tighten Up!


Photo from

Every six months I go around to every connector and screw terminal in my station and make sure everything is tight. Many noise problems come from connections or connectors that are not properly seated or tight. It is amazing what I find!

Now is also a good time to inspect your station cables. Control cables and Coax cables do age and can get damaged. So, before bad weather sets in, inspect your cables and the connectors on them.

It is a good idea to check your antenna VSWR. If it got better or worse since the last time you checked it, that can be a sign that something has changed and needs to be investigated.

Thanks for reading, and check back each week for new Tech Tips!

– Tim Duffy, K3LR

The Icom IC-7300 has a very nice built-in iambic keyer that can be used with a single lever or dual lever (iambic) paddle.

While this is a good feature, many “brass pounders” like to use their own external keyer, bug or straight key.

Some larger and more expensive radios have separate paddle and key jacks. The single key jack on the IC-7300 serves either as the input connector for a paddle, or as the input for your external keyer, bug, or straight key. Switching from one to the other requires some proper plug wiring and menu changes.

The Icom 7300’s Full Manual shows how to connect your paddle or key to the key jack in the following illustration using a ¼-inch stereo plug, which has 3 connections: Tip (dot), Ring (dash), and Sleeve (com):

Key Jack

For your straight key, bug, or output of your external keyer, connect to the “Tip” (+) and the “Sleeve” (-, or com) only – 2 connections. For the paddle input to the internal keyer 3 connections (dot(dit), dash(dah), and ground) you use the Tip for the “dot”, the Ring for the “dash”, and the Sleeve

Once the physical connections are made, you’re ready…but the internal keyer is still active! If you’re using a straight key, every time you press the key you’ll get a string of “dits” from the internal keyer. So, what do you do?

You have to turn off the internal keyer and set the key jack to “straight key” input mode. It is not readily apparent how to do this with the 7300 as it defaults to using the internal keyer. There is also no “using a straight key” section in the manual.

DX Engineering has put together a PDF file that augments the 7300’s manual for this purpose. You can download this PDF along with the full manual for the 7300 and other IC-7300 related documents here.

Receiving weak stations with very low signal levels on frequencies from below the AM broadcast band up through the shortwaves of HF often requires the use of a specialized antenna system that improve the signal-to-noise ratio (s/n). This is simply explained by the statement: “You cannot understand an S-2 signal level below S-5 noise level.”In order to hear those weak stations, you’ll need to deal with the noise!

DX Engineering RF-PRO-1B Active Magnetic Loop Antennas RF-PRO-1B

DX Engineering RF-PRO-1B Active Magnetic Loop Antenna

There are different approaches to mitigating noise. Most involve using some sort of receive-only antenna. One popular method is to use an Active Magnetic Receiving Loop (DXE-RF-PRO-1B). These directional antennas are extremely broad-band, easily covering the frequency range from 500 kHz to 30 MHz. Because they respond to the magnetic field as opposed to the electrostatic field of radio waves, they are inherently very quiet receiving antennas. Their loop mounted preamplifier powered by DC on the feedline is what makes “active” magnetic loop antennas boost their low-noise received signal.

Shortened verticals are popular SWL/AM DX/Amateur Radio receiving antennas (DXE-ARAV3-1P) for use over the same frequency range. Because of their physical length they “capture” less noise. These omni-directional receive antennas use special low-noise active preamplifiers to boost the low signals and their “amplifier” active circuit is mainly used to provide a broadband match to the feed line.

DX Engineering Receive Four-Square Array Electronics Packages DXE-RFS-SYS-3P

DX Engineering Receive Four-Square Array Electronics Package

Short verticals are ideal for use in a phased array known as Receive Four-Square array (DXE-RFS-SYS-3P) or 8-Circle arrays (DXE-RCA8B-SYS-4P), because these short antennas are very noise resistant. Vertical phased arrays produce a directional receive pattern with a peak lobe that can be “steered” away from the interference, and to steer the null in the pattern onto the QRN and QRM, so you can hear the desired signal.

It is also possible to use an active receive antenna as a “sense antenna” to deliberately collect noise and interfering signals and shift them out of phase with another receive antenna (or transmit antenna) to create a directional null or dip in reception. This is an extremely effective way of reducing or eliminating noise at the receiver. Phasing units are available with many different features and typically vary in price according to their features and effectiveness (DXE-NCC-1, DXE-NCC-2). It is possible to phase two active receive antennas with each other, or to phase a receive antenna with the received signal from a transmit antenna.

All of these suggestions involve use of receive-only signals. When you need to connect a receive antenna system to a transceiver equipped with a single antenna port, use a receive antenna interface unit (DXE-RTR-1A, RTR-2, NCC-2). These units allow automatic switching and protection for receive-only systems when you don’t have RX-only transceiver input.

Unlike 30 years ago, there’s no reason to be foiled by noise. Single, or even multiple methods, may be used to deal with unwanted noise. Then you can grab the weak ones!

Sometimes our tech tips are very detailed. Other times, we try to highlight easy ways Hams can solve problems they frequently encounter.

In today’s Ham Radio Tech Tip, brought to you by DX Engineering Technical Writer Tom Parkinson, KB8UUZ, we highlight math conversions.

Need a handy chart for converting inches, fractions and millimeters? Check out this FREE chart on DX Engineering’s web site.

Make a copy, get it laminated, and it will be there to aid in your next ham radio project. We have also included the chart below: