Ham College 93


Ham College episode 93 is now available for download.

Extra Class Exam Questions – Part 31.
E7B Amplifiers:(part 1 of 2) Class of operation, vacuum tube and solid-state circuits, distortion and intermodulation, spurious and parasitic suppression, microwave amplifiers, switching-type amplifiers.

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George Thomas, W5JDX, is co-host of AmateurLogic.TV, an original amateur radio video program hosted by George Thomas (W5JDX), Tommy Martin (N5ZNO), Peter Berrett (VK3PB), and Emile Diodene (KE5QKR). Contact him at [email protected].

Amateur Radio Weekly – Issue 256

Amateur Radio Weekly

Hams continue response to Ian
Over 125 specific reports have been filed to the National Hurricane Center.
ARRL

Amateur Radio Satellite from Zimbabwe
Zimbabwes first satellite ZimSat-1, carrying an Amateur Radio APRS digipeater is expected to be be launched to the ISS in October.
Southgate

A cheap amplifier kit off Aliexpress for a few bucks
It worked, but not very well. The input SWR was 5:1.
awsh.org

Hams you should know: Walter Cronkite, KB2GSD
Known among radio enthusiasts as the most trusted Ham in Amateur Radio.
OnAllBands

Build an HF Ham Radio dipole antenna
Use a few simple components at a minimal cost and get great results.
Electronics Notes

Similarities of current Yaesu rigs
Yaesus about-to-be-available FT-710 is a curious specimen.
AE5X

QDX is an excellent digital modes transceiver
What is astonishing is how good the transmit is.
marxys musing on technology

What do VHF and UHF mean?
We toss around these terms quite loosely even though they have precise definitions.
K0NR

BBC announces World Service cutbacks
BBC to end production of radio output in 10 languages.
Guardian

Detecting Starlink Satellites with a portable Raspberry Pi
Starlink beacons typically transmit at around 11.325 GHz.
RTL-SDR.com

Video

Is Your House Bugged?
A current loop microphone can provide audio surveillance at low cost and high fidelity.
Leos Bag of Tricks

Solved: RF interference from light dimmer switches
Quin and Tom explain how to get rid of RF interference.
Ham Radio Perspectives

HF & Shortwave on the RTL SDR
Ive received many questions if this can be done, and the short answer is yes.
Tom the Dilettante

NØVCU boat anchor collection
In the shop he has many Swan transceivers, Collins, Drake and Cubic.
K0PIR

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Amateur Radio Weekly is curated by Cale Mooth K4HCK. Sign up free to receive ham radio's most relevant news, projects, technology and events by e-mail each week at http://www.hamweekly.com.

What Do VHF and UHF Mean?

Recently, I engaged in a discussion about a UHF (Ultra High Frequency) radio. It seems a ham was complaining that someone had advertised an 800 MHz radio, describing it as “UHF”. His issue was that in land mobile radio, UHF is commonly used to refer to radios in the 380 to 500-ish MHz range. I disagreed with him, saying that 800 MHz is in the UHF range I was using the ITU definition of UHF, which is any frequency between 300 MHz to 3 GHz. The disagreement was not a big deal but it did cause some confusion. (Of course, I was right and he was wrong, most definitely.)

This got me thinking about how we toss around these terms quite loosely, even though they have precise definitions. Let’s start with the basics, the ITU definitions of radio spectrum.

LFLow Frequency30 to 300 kHz
MFMedium Frequency300 kHz to 3 MHz
HFHigh Frequency3 MHz to 30 MHz
VHFVery High Frequency30 MHz to 300 MHz
UHFUltra High Frequency300 MHz to 3 GHz
SHFSuper High Frequency3 GHz to 30 GHz

You can see that the basic scheme divides up the spectrum into decades (factors of ten), aligned with frequencies that start with 3 (e.g., 3 MHz, 30 MHz, 300 MHz). If we map the amateur bands onto this system, we see that the bands from 80m (3.5 to 4.0 MHz) through 10m (28-29.7 MHz) fall into the HF range, as expected. Note that 10m almost qualifies as a VHF band, coming in just shy of the 30 MHz limit. That band does have some VHF tendencies. The 160m band (1.8 to 2.0 MHz) actually falls into the MF range even though many of us just think of it as HF.

Let’s take a look at how the US amateur bands line up with this scheme.

Amateur bands within HF, VHF, and UHF ranges. (Some omissions for legibility: 60m, 17m, 12m HF bands.) Graphic: HamRadioSchool.com

There are three VHF bands: 6m (50 to 54 MHz), 2m (144 to 148 MHz) and 1.25m (222 to 225 MHz). The UHF range includes the 70 cm (420 to 450 MHz), 33 cm (902 to 928 MHz), 23 cm (1240 to 1300 MHz), and 13 cm (2300 to 2450 MHz) bands.

The two most commonly used bands in the VHF/UHF region are 2m and 70cm. These bands are home for many FM repeaters, FM simplex, SSB simplex, and plenty of other modes. Common dualband transceivers, both mobile and handheld, operate on the 2m and 70cm bands. These radios are so common that we often refer to them as VHF/UHF dualband radios. Accordingly, you will often hear hams refer to the 2m band as simply VHF and the 70cm band as UHF, as if VHF means 2 meters and UHF means 70 cm. I know I’ve been guilty of saying “let’s switch over to VHF” when I really mean “let’s go to the 2m band.” The 2m band is certainly VHF but VHF does not always mean 2 meters. Similarly, we might say “I’ll call you on the UHF repeater” when it would be more precise to say “I’ll call you on 440 MHz.”

Many times being loose with terminology doesn’t matter but there are times when using the right words can make a difference. Think about this the next time you are referring to a particular frequency band.

73 Bob K0NR

The post What Do VHF and UHF Mean? appeared first on The KØNR Radio Site.


Bob Witte, KØNR, is a regular contributor to AmateurRadio.com and writes from Colorado, USA. Contact him at [email protected].

LHS Episode #482: Linux Network Utilities Deep Dive

Hello and welcome to Episode 482 of Linux in the Ham Shack. In this episode, the hosts take an in-depth look at some common network utilities on the Linux command line to help you configure, monitor and troubleshoot your computers' network connections. We hope you find this episode informative and entertaining. Please send us feedback and we look forward to catching you for the next installment.

73 de The LHS Crew


Russ Woodman, K5TUX, co-hosts the Linux in the Ham Shack podcast which is available for download in both MP3 and OGG audio format. Contact him at [email protected].

SOTA Success on Red Mountain #3

Last year, Joyce/K0JJW and I tried to activate Red Mountain Number 3 (W0C/UR-016) for SOTA in the San Juan mountains. The map showed there was a road to the top, so we were expecting easy access. However, the road is gated off about 2 miles from the summit, requiring a hike. So we hiked almost to the summit but turned back when the thunderstorms rolled in. We retreated to safety and vowed to return another day.

Red Mountain Number 3 as viewed from Red Mountain Pass.

This week, we went back and activated the summit, along with Stu/W0STU and Liz/KT0LIZ. Red Mountain No. 3 sits just southwest of its sister summits: Red Mountain No.1 and Red Mountain No. 2. (Red Mtn 1 is also a SOTA summit, so we’ll need to activate that one sometime.)

We accessed Red Mountain 3 (RM3) by taking Highway 550 to Red Mountain Pass. The road for RM3 is County Road 14 but is not well marked. The turnoff (shown on the map above) is just south of Red Mtn Pass, going to the east (37.89587, -107.71369). County Road 14 is a narrow but easy road, barely 4WD, that leads to the gate (37.89476, -107.70774). We parked there and hiked up the road.

Sign on the gate that welcomes hikers, skiers, and cyclists.

I don’t usually like to hike on roads but this one turned out to be just fine. It was a nice, easy grade and was flat without a lot of rocks poking up. My GPS app shows that we hiked 2 miles one-way with 1400 vertical feet. We met about a dozen people on the hike, so this seems like a popular summit. We noted other trails and roads in the area and wondered if some of them might provide a better route but everyone we saw just used the road.

 

As you can see from the photos, we had excellent weather that day. This time, no thunderstorms to chase us off the peak!

Stu/W0STU examines his VHF/UHF handheld, positioning it for optimum signal level.The San Juan mountains are remote, with not a lot of people within VHF range. We were all using just VHF/UHF for SOTA, so I was concerned we could get skunked on making our four SOTA contacts. There are a few smaller towns within range and we might be able to work Grand Junction from there. I knew that Lloyd/W7SAO in Delta usually monitors 146.52 MHz and we worked him right away. After that, we called our fellow campers, James/KD0MFO and Vic/KD0OGE, working them mobile near Ridgway. We kept calling for a fourth contact and sure enough, Mike/KE5YF showed up on 2m FM. Mike is from Sweetwater, TX and was driving his Off-Highway Vehicle (OHV) over Engineer Pass. So we made our four contacts to qualify for SOTA points.

Traditional summit photo: Stu/W0STU, Liz/KT0LIZ, Joyce/K0JJW, Bob/K0NR

 

Liz and Joyce are hiking on a typical stretch of the road.
Bob/K0NR operating 2m FM for SOTA. (Photo: W0STU)

The four of us had a great day on the summit. We took our time and enjoyed the hike and the radio operating. The easy access and excellent views from the top make this an attractive SOTA summit if you are traveling in this area.

73 Bob K0NR

The post SOTA Success on Red Mountain #3 appeared first on The KØNR Radio Site.


Bob Witte, KØNR, is a regular contributor to AmateurRadio.com and writes from Colorado, USA. Contact him at [email protected].

SOTA Success on Red Mountain #3

Last year, Joyce/K0JJW and I tried to activate Red Mountain Number 3 (W0C/UR-016) for SOTA in the San Juan mountains. The map showed there was a road to the top, so we were expecting easy access. However, the road is gated off about 2 miles from the summit, requiring a hike. So we hiked almost to the summit but turned back when the thunderstorms rolled in. We retreated to safety and vowed to return another day.

Red Mountain Number 3 as viewed from Red Mountain Pass.

This week, we went back and activated the summit, along with Stu/W0STU and Liz/KT0LIZ. Red Mountain No. 3 sits just southwest of its sister summits: Red Mountain No.1 and Red Mountain No. 2. (Red Mtn 1 is also a SOTA summit, so we’ll need to activate that one sometime.)

We accessed Red Mountain 3 (RM3) by taking Highway 550 to Red Mountain Pass. The road for RM3 is County Road 14 but is not well marked. The turnoff (shown on the map above) is just south of Red Mtn Pass, going to the east (37.89587, -107.71369). County Road 14 is a narrow but easy road, barely 4WD, that leads to the gate (37.89476, -107.70774). We parked there and hiked up the road.

Sign on the gate that welcomes hikers, skiers, and cyclists.

I don’t usually like to hike on roads but this one turned out to be just fine. It was a nice, easy grade and was flat without a lot of rocks poking up. My GPS app shows that we hiked 2 miles one-way with 1400 vertical feet. We met about a dozen people on the hike, so this seems like a popular summit. We noted other trails and roads in the area and wondered if some of them might provide a better route but everyone we saw just used the road.

 

As you can see from the photos, we had excellent weather that day. This time, no thunderstorms to chase us off the peak!

Stu/W0STU examines his VHF/UHF handheld, positioning it for optimum signal level.The San Juan mountains are remote, with not a lot of people within VHF range. We were all using just VHF/UHF for SOTA, so I was concerned we could get skunked on making our four SOTA contacts. There are a few smaller towns within range and we might be able to work Grand Junction from there. I knew that Lloyd/W7SAO in Delta usually monitors 146.52 MHz and we worked him right away. After that, we called our fellow campers, James/KD0MFO and Vic/KD0OGE, working them mobile near Ridgway. We kept calling for a fourth contact and sure enough, Mike/KE5YF showed up on 2m FM. Mike is from Sweetwater, TX and was driving his Off-Highway Vehicle (OHV) over Engineer Pass. So we made our four contacts to qualify for SOTA points.

Traditional summit photo: Stu/W0STU, Liz/KT0LIZ, Joyce/K0JJW, Bob/K0NR

 

Liz and Joyce are hiking on a typical stretch of the road.
Bob/K0NR operating 2m FM for SOTA. (Photo: W0STU)

The four of us had a great day on the summit. We took our time and enjoyed the hike and the radio operating. The easy access and excellent views from the top make this an attractive SOTA summit if you are traveling in this area.

73 Bob K0NR

The post SOTA Success on Red Mountain #3 appeared first on The KØNR Radio Site.


Bob Witte, KØNR, is a regular contributor to AmateurRadio.com and writes from Colorado, USA. Contact him at [email protected].

ICQ Podcast Episode 386 – Tips from the Shack

In this episode, we join Martin M1MRB, Frank Howell (K4FMH), Martin Rothwell (M0SGL) and Bill Barnes (WC3B) to discuss the latest Amateur / Ham Radio news. Colin (M6BOY) rounds up the news in brief and in the episode's feature Tips from the Shack.

We would like to thank our monthly and annual subscription donors for keeping the podcast advert free. To donate, please visit - http://www.icqpodcast.com/donate

- Amateur Radio Helps Disabled Sailboat to Port

- Radio Amateurs are not Afraid of a Blackout

- The Largest Commercial Communications Array ever has just Launched

- 104-year-old Radio Ham is on the Air

- First 40 MHz SSB contact between UK and South Africa

- 40th Annual AMSAT Space Symposium and General Meeting

- Videos from Digital Communications Conference 2022

- Latest Version of RSGB EMF Calculator


Colin Butler, M6BOY, is the host of the ICQ Podcast, a weekly radio show about Amateur Radio. Contact him at [email protected].

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