WA2ISE ham radio equipment


HF:

Ham for quarter century now. Before that I had "KAAR5167".
"A bad day on 10 (meters) is better than a good day at work."

TS440S mod for increasing sensitivity on the MW AM broadcast band: (Removes MW attenuator pad). The TS440S has an attenuation pad hard wired on the spectrum between 500KHz and 1600KHz. You can open up sensitivity by removing it. On the RF unit board, clip a lead on R13 (68 ohms), clip a lead on R14 (68 ohms), and solder a jumper across R12 (220 ohms). These are under a shield held down by screws on the RF board. I've noticed no intermod problems and only the strongest stations (above S + 40) overload (which can be solved by using the front panel attenuator button). Proceed at your own risk.

Build an RFI sniffer:


To track down exactly where RFI is coming out of a computer or other equipment, use this RFI sniffer. It's a ferrite toroid ring with a gap cut into it. Several turns of wire connect to coax that then feeds into a receiver or spectrum analyzer (I'm sure you have one handy!). The gap is the sensitive area. It will pick up RFI magnetic fields. Thus you can identify wires or other leakage areas with RFI on them.

It takes a long time to file the gap into the toroid; your needle files will get dull. Don't push too hard, as ferrite is fragile. You want a narrow gap on the outside part of the ring, so file from the inside. A gap about the thickness of a fingernail is good. Depending on the ferrite material, this sniffer should be good for HF and VHF.

For low frequency work, use a tape head from an audio cassette machine. The center of the front part of the head (where the tape used to pass over) will be the sensitive spot.

HF antenna tuner:
A low pass filter cutoff at 50MHz

Using this filter on the HF rig, probably don't need it, but I have it so I'll use it. Haven't "Worked All Neighbors" yet!


My father WB2JIA (SK) used this for code practice. Clock radio modified for GMT 24hr "zulu" time.

6 meters:

2 meters:
A dual band HT:

States I've worked so far (*):

Worked All Continents


Elroy on his interplanetary ham station. He has a "worked all planets" award.
QRZ callsign lookup:
Input a callsign:
download a VHF twinlead Jpole antenna calculator MSDOS program
Building a 1 : 1 coax balum for HF use:

Using ferrite material intended for RFI work on ribbon cable, (which cost me 50 cents apiece surplus)
Fig 1:
One can build a ferrite core toroid using the above ribbon cable clamshell ferrite bars. The bars shown here measure about 2cm wide by 5cm long and 5mm thick. Not critical. You will need 8 such bars.
Fig 2: Arrange them such as this.
Fig 3:
The flat sides of the clamshells go up against each other for a tight fit.

And the finished product looks like this with about 15 loops of feedline coax thru the center of the new toroid. I used packing tape to hold the ferrite bars together. Better tape may be needed if it will be outdoors. I taped together the bars in two sections as seen in Fig 2 so I could place both sections around the existing loops of coax. Thus I avoided having to thread coax thru the center hole had I created the complete toroid first.
Fig 4:
I am now able to load up my attic dipole antenna from 80 to 15 meters using the automatic tuner in the above TS440S. The toroid keeps RF off the outside of the coax feedline. Otherwise the tuning can be messed up by such RF running down the feedline into the shack.

Vacuum tube crystal tester

A crystal tester using a 6AH6 tube. Has a "crystal activity" 500uA meter, and an output jack for feeding a frequency counter or such. My father WB2JIA (SK) built this back in the 50's or 60's. It pretty much can do any crystal you toss at it.

Listening to subcarriers on FM broadcast stations with the TS440S and similar radios:

As the TS440S can receive signals all the way down to 30KHz all modes (AM, FM, USB, LSB, CW), you can "surf" the SCA subcarriers on the FM broadcast band. Usually found as FM modulation at 67kHz and 92kHz, and RDS/EAS at 57kHz (use the FSK demod on the TS440SAT at about 58 or 59kHz). Also those of TV stations on their sound broadcasts. These are usually found as FM modulation at 78.67kHz (SAP channel), and a cue channel at 102.27kHz.

What you need to do is tap the output of the main FM carrier detector before the deemphasis circuit in an FM broadcast band radio or TV set. A cheapie AM/FM clock radio or TV set will do at first. The deemphasis circuit is usually an RC low pass filter. One way to "hunt" for this point is to hook up an audio amplifier to a test probe, and find a node on the circuit board that has main channel broadcast audio with lots of treble as compared to that found at the top of the volume control. If you can't find such, take a look for a small cap (on the IC pin with the audio demod out) that goes to ground which in combination with a resistor may be the deemphasis network. Try disconnecting the cap. One this spot has been identified, connect a 0.01uF cap in series with a 1K resistor, and that then in turn feeds the center conductor of a length of thin coax. The coax ground connects to the radio ground. The other end of the coax connects to the TS440S antenna input. Check that the FM broadcast radio still plays, as the coax cable is now loaded with 50 ohms impedance.

If you have an older mono FM tuner like an Eico HFT90, connect to the multiplex output jack (the one intended to feed an external stereo demodulator) and use a resistor of around half a meg in the signal path from this jack to the TS440SAT receiver. This will avoid excessive loading of the normal mono output signal (so you can listen for FM stations' main mono audio channels).

Disconnect the mic on the TS440S so you don't accidentally transmit into the FM radio! Tune in 38KHz in USB mode. Now tune around on the FM broadcast radio. You should be able to hear the "difference" (L-R) audio signal of FM stereo stations. You should be able to notice the usual lack of vocals in most songs, as compared to the FM broadcast radio's mono speaker output. Assuming success, try tuning in 67KHz FM mode on the TS440S. Now tune around on the FM broadcast radio. You may find various foreign language programs and data transmissions. Also try 92KHz FM on the TS440S. Expect about 10% of FM broadcast stations to have subcarriers. Don't overlook the college radio subband from 88 to 92 MHz.

You're essentially "surfing" the radio spectrum in two dimensions, one "axis" is the FM broadcast band, and the other is each FM station's subcarrier signal spectrum.

Modifying toy 49MHz AM walkie talkies for 6 meters:

For some super cheap local QRP comm work, modify 2 or more of those cheap AM superregenative 49MHz walkie talkies Radio shack or KB or other toy stores sell for less than $10 a piece. I found a small quantity of surplus crystals at 50.3714 MHz for 79¢ each. These particular ones look like TO3 transistors, but they fit in the talkies. Of course, try out the talkies before mods are done. Then replace the 49MHz crystal with the new 6 meter crystal. Then using a real 6 meter rig receiver tuned to the new crystal frequency or a counter, check the carrier frequency when transmitting with the modified talkie. If you need to, you can adjust the frequency adjust coil. See pictures to see what this coil usually looks like. I used the above mentioned crystal as it puts me into the "all mode" subband, where AM is proper. Be sure to mark the modified talkies as ham rigs, and only let hams use them.