Questions tagged [vhf]

Very High Frequency is the frequency range 30-300 MHz.

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3
votes
2answers
457 views

2 meter dipole of work vehicle

I am about to purchase a Baofeng HT. I have one I am thinking of using primarily in work truck. I can't really drill holes or have antenna be too obvious. On Amazon I found a 2 meter 70cm 2m dipole....
1
vote
2answers
551 views

Airband VHF antenna challenge

I have a very difficult antenna design/installation challenge. I need to install an VHF antenna (118 to 140 MHz) into a nearly all carbon fiber glider. The radio provides 5 watts and 50 ohm, and most ...
1
vote
1answer
94 views

Antenna for 6M, or Antenna system?

Here, in VU-land, 6M allocation is from 50 MHz through 54 MHz... which is a fair chunk of spectrum. If I think about a half-dipole antenna; between 50/54 MHz it's length varies by over a foot ... and ...
1
vote
1answer
788 views

VHF / UHF - Terrestrial Circular Polarized Antenna

I've been doing mostly HF for the last 20 years and just recently installed a 2m/70cm mobile rig in my shack for base station work. I like to work FM simplex and repeaters when the HF bands are not ...
1
vote
1answer
419 views

What is the best resonator in Yagi antennas?

As we saw many design for this Yagi feed point. Q1 . Which one would be the best resonator / driven? Gamma match, T-match, delta match, folded dipole, quad, loop? Q2. And what is the reason if ...
16
votes
3answers
7k views

What's wrong with 220MHz?

It seems like 220MHz is the bastard step-child of the amateur world. Every HT is either 2m or 2m/70cm. Some companies offer tri-banders, but they almost always add 6m (?!), not 220MHz. The only way ...
6
votes
2answers
375 views

Weather Imaging with NOAA satellites - legal?

I would like to build an antenna for receiving NOAA weather satellites. They're receivable at around 137.5 Mhz. I'm a total new to amateur radio stuff. I know that it's not legal to communicate as ...
2
votes
3answers
126 views

Identifying Local Signal

I've been monitoring a signal locally on 159.150mhz (which is allocated for "Civil Defense"). I believe that this frequency is for the local tornado sirens and I would like to be able to decode the ...
2
votes
4answers
172 views

Colorado to Ohio with UV-5R

My brother (in Ohio) just passed his Technician test. We both have UV-5R equivalent radios. I have my General (in Colorado). Without physical modifications to our radios, can we have a QSO? I've been ...
9
votes
1answer
770 views

Is a modded Yaesu FT-270r acceptable to use on MURS frequencies?

I am a bit new to the radio scene, so excuse me for any ignorance that may follow. I saw on a website that you could mod the Yaesu FT-270r so that you can increase its transmission range outside of ...
2
votes
0answers
259 views

How can I connect a CW keyer to my Mac and transmit CW on VHF? [duplicate]

I currently have a Kenwood TM-V71A 2m/70cm transceiver that I would like to connect to my Macbook to transmit morse code, using the cocoaModem software. Aside from the cables needed to connect the ...
2
votes
1answer
433 views

VHF antenna / receiver suggestion for a UAV

I am currently working on a student project that involves having a UAV fly an orthogonal path over a series of transmitters -- taking in data (through an arduino-based system for data processing). ...
3
votes
2answers
270 views

Using square loop VHF antenna for two different stations/frequency?

I'm using a square loop antenna on the rooftop of approximately 15 square meter area. I use it to communicate with a group of mobile VHF radios using a station room. Right now I'm planning to build ...
12
votes
2answers
269 views

Why do satellites receive and transmit on different bands?

Most satellites I've found transmit on VHF and receive on UHF or vice versa. Why is this? I would think there's enough space on a single band.
11
votes
2answers
680 views

Getting Started with Digital Modes on VHF on Linux

I am interested in learning about digital modes using 2m and Linux. I have a couple of older 2m rigs (HTX-212 and an old Yaesu) with no additional hardware, like a TNC. What current resources exist ...
6
votes
1answer
2k views

Effect of night on VHF/UHF propagation

I have had some conflicting experiences relating to the effect of night time (ionosphere, temperature, etc.) on propagation. Perhaps it is related to the frequency of what I was working with. ...
3
votes
2answers
1k views

2m Homebrew Receiver - Chip for frequency [closed]

I am a new HAM trying to design a small, cheap 2m receiver. I've been looking up different circuits and homebrew tutorials, but the closest I seem to find to what I'm looking for seems to always use ...
5
votes
2answers
440 views

Circuit to send MCW on 2m FM

I regularly practice Morse with a friend on 2m NFM by holding our tone generators, which we also use for personal practice, close to the microphone. We send text by CW, read it back, and discuss how ...
4
votes
1answer
311 views

2 m meteor scatter FM voice freq?

What frequency should I use to try and make meteor scatter contacts on 2m FM tonight, with a nice meteor storm coming?
3
votes
2answers
2k views

Choosing simplex frequency as a technician

My brother and I just got our technician class license. We live close enough to each other that we can use simplex on 2 meters or 440. How do we go about choosing the best frequency to use?
4
votes
3answers
611 views

Height and feedline loss tradeoff for VHF

Currently my 2m antenna is about 3m above the ground inside, my HF antenna is connected to 30m (2db loss) coax and is about 12m up. Since the loss for 2m is a lot more when traveling down such a long ...
8
votes
4answers
10k views

How to improve VHF/UHF Baofeng UV-82 HT reception in vehicle

I have a Baofeng UV-82 dual-band (2m/70cm) HT with an SMA male connector for the stock "rubber-ducky" antenna. I would like to use it in my vehicle. I would like a high-quality magnetic mount dual-...

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