# All Questions

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96 views

### Can I use the dummy load provided with the nanoVNA for adjusting my QCX+

I don't see any mention about the dummy loads rating. Since I'm operating at $13.8~V$ the power output is about $4~W$. I'm looking to use what I have on hand as I have a field day approaching soon and ...
125 views

### Heat-shrink as dielectric for bazooka balun?

I'm intending to make a sleeve balun (aka bazooka) for 2m, but rather than keep the lossy coax jacket as a dielectric (I have some RG58), was considering to remove it and replace it with heat shrink ...
62 views

Helping a friend with his RFI problem. He has a SDR HF radio and Hustler BTV antenna with a toroid choke and about 32-radials. He has vertical bars on his panadaptor around 20 khz apart, mainly on 40M....
153 views

### Is the ARRL website distributing malware? I'm not sure who to contact

When I was visiting the ARRL/become a VE site on my iPhone and I try to download the PDF for the application form, it redirects me to a malware site. I have confirmed this with other ham friends and ...
64 views

### Are there countries where QSLs are required to get or upgrade a license?

I've heard that there are countries where you start as SWL and have to collect some number of QSL cards to get a license. Or maybe there are places where QSLs are required to upgrade a license and get ...
101 views

### I just can't get out on my car mounted HF

Would love some advice from you seasoned vets. I have an FT857D in my car which I tend to only use (and really want to use) when I'm stopped and setup camping. I bought a portable Windom antenna which ...
77 views

### What is the best frequency to start working EME on a budget?

Well, the title says it all: I want to start making EME contacts with the lowest possible budget, and I doubt between 2m, 70cm and 23cm. Since I cannot afford those expensive power amplifiers for ...
68 views

### Lab599 Discovery TX-500 connectors?

The Lab599 Discovery TX-500 is coming out soon. A lot has been said about that radio's use of weather-resistant proprietary connectors, but what are the actual connector types? The antenna is female ...
69 views

### Will using a loaded coil antennas have detrimental effects on QRP operations?

I was looking for a 40 m antenna for QRP CW operation at 3 W. I looked at the Wolf river coil which is a nice portable antenna. From speaking with other hams they mentioned loaded coils are poor for ...
79 views

### How does this W6NBC “derivative of the classical slot antenna” work?

Via the https://ham.stackexchange.com/a/9883/1362 answer regarding a slot antenna for a 2m mobile application, I was introduced to this (pdf) interesting antenna design: The designer John Portune (...
72 views

### Baofeng UV-9 Info and Help Please!

I have scoured the internet for info on this radio. Specs, programming, manuals, to be exact, yet I can find NOTHING other than sellers of the radio. Anyone have any links they'd be able to share! I ...
534 views

### How to increase the bandwidth of half-wave dipole antenna?

I have designed a half-wave dipole antenna for frequency range of 150 to 200 MHz. Due to resonant frequency of 175 MHz, Its dimensions are: L=817.44 mm, R=1.71 mm. Impedance is also equal to 73 ohms. ...
107 views

### Does 3 W vs 5 W TX power make a huge difference in QRP CW operation?

I've bought the QCX+ 40 m band radio. I will be powering this off a 12 V battery. I read on the manual the RF power at 12 V is just 3 W whereas on 15 V it is 5 W. Should I buy a boost converter for ...
67 views

### How do you open ax.25 ports?

I'm trying to follow this tutorial I almost got to the end, about 9:15 was where I got stuck. Right about there, the speaker is about to wrap up- but I get a couple error messages. ...
89 views

### For the FT-60R, does the NC-88B power supply work with the YAESU SBH-13 charging cradle?

I bought a Yaesu FT-60R years ago. Instead of coming with a charging cradle, it came only with the NC-88B power supply. The NC-88B power supply isn't very intelligent--I don't believe it stops ...
79 views

### Talk Around vs Reverse

I thought that "Talk Around" and "Reverse" were two ways of referring to the same thing: swapping a channel's transmit and receive frequencies so that one could e.g. listen for ...
132 views

### Hunting RFI with bars every 61 khz

I realise there have been many great posts on hunting RFI, i've got pretty close to tracking mine down, but would appreciate some insights from the ham.se experts :) I've done quite a lot of work to ...
80 views

### Yagi performing far worse than a dipole

A few months ago, I built a 6 element yagi: 3 driven elements, and 3 reflectors. For 10-15-20m. I was able to tune it to SWR 1:1 for the FT8 frequencies in each band. This antenna is only 6m above ...
77 views

### How to track down and neutralize this apparent mixer creating noisy emissions around my signal?

When I transmit, it there seems to be something mixing and reflecting my signal. For example, when I transmit on 14.300 MHz, I see signals above my transmitted signal at at 14.500, 14.700, 14.900, etc....
82 views

### what frequencies is this antenna cut for?

I just bought a magnet-mount whip antenna at a garage sale. It has no brand markings anywhere on it. it is 32" long overall but is broken up into three segments by what appear to be two small ...
82 views

### How does PTT from one two-way radio prevent input on another?

I'm very much a beginner with radio. I have a simple set of Baofeng BF-888S radios, and in my basic use with those, I got very curious about something: when you push the PTT button on one radio to ...
45 views

### Where can I find a table listing the maximum PEP per band?

I'm building myself an Excel Cheat Sheet.
229 views

### Does the output of a BFO for a short wave receiver have to be exactly a sine wave?

I want to build an external beat frequency oscillator (BFO) for an old valve Eddystone receiver I have. There are many circuits for BFOs on the internet, they are mostly similar, the idea seems simple ...
48 views

### Resources and guidance regarding APRS

I know getting my Technician License is the place to start, however, I have in my head a clear path that I want to achieve and am looking for guidance for the most efficient way to achieve that goal. ...
137 views

### How do I know if my coax connectors are good?

In installed a couple of compression style PL-259 connectors to the ends of RG8/U FOAM coax. It's about 16 feet in length. Here is an example of one of the connectors: How do I know if the coax is &...
21 views

### how to set the CFO standard deviation in CFO models

I need some help with a simple thing. I am trying to simulate carrier frequency offset model for Bluetooth Low Energy standard in GNURadio (I am bit new to this). For this purpose, there is a CFO ...
70 views

### What is an Audio Peaking Filter?

What is an Audio Peaking Filter? And how might that be different from an ordinary (narrow) CW bandpass filter, or from tunable audio filters (with fully configurable upper and lower cutoffs)? Does a ...
151 views

### Which cable is better for ham radio antenna? RG58, RG59, or RG6? [closed]

Which cable is better for ham radio antenna? RG 58, RG 59, or RG 6? Based on [1], RG6 has lower signal loss. So, is RG 6 a better cable? Or there are no differences? [1] https://sewelldirect.com/blogs/...
83 views

### How to estimate input and output impedance of an amplifier?

I'm trying to figure out how to design power amplifiers which input and output are properly matched to 50 Ohm. My thinking was that the most bullet proofed approach would be to model an amplifier in ...
189 views

### What are these antennas?

On a recent trip to China I photographed a number of "antennas" that I do not recognize. Are they even antennas?
112 views

### What is the difference between RIT and XIT?

What is the difference between RIT and XIT? When would one use one and not the other for split (or other) HF operation? When would one need both? Which one is more useful for a transceiver to have ...
50 views

### Omni 144 MHz antenna

I plan to build omni antenna. My goal all about better gain versus a 1/4 wave antenna. I am curious about radial position of the legendary ARX2B Ringo Ranger. Why is the position in below feed point? ...
352 views

### What is the use of dual VFOs?

What is the value of more than one VFO in an HF transceiver? Many novice rigs only have a single crystal oscillator, and a vast number of famous classic transceivers, HF kits, and QRP rigs only have a ...
125 views

### Does Improving Earth Conductivity Near a Buried Ground Rod Improve Antenna System Performance?

The suggestion has been made on various ham-related websites that improving the conductivity of the Earth around a ground rod produces a worthwhile improvement in the e-m radiation from a vertical ...
92 views

### Built a 2 meter 5 element Yagi

Straight dipoles. I can't get the Yagi to tune. I have tried the 4:1 Balun method with coax but not able to tune. With the straight unbalanced input to the dipole I get a 1:1 swr on about 129 MHz ...
59 views

### String in APRS report

Here are two messages I received: ...
98 views

### DIY Triplexer for HF (low), 6m (med), and 2m/440 (high)

I'm looking at picking up the TYT TH-9800, which is a Quad-Band FM radio on 10m/6m/2m and 440 (I'm lucky enough to have some 6m and 10m repeaters in the area). I know there exists quad band antennas ...
49 views

### How to use OFDM Synch in GNU Radio?

I am transmitting OFDM 16-QAM x 6 carriers packets using the python library amodem and a HackRF. My setup is very simple for the transmission side, it takes the .wav generated by amodem from data and ...
134 views

### If the data port on a Yaesu FT-7800R only communicates FM signals, why does the manual mention the port having a bit rate?

I was wondering how the Radio interfaced with a TNC. I thought the computer sent digital data (in a serial format) to the data port on the radio, but from what I read online, it is not a data port. ...
144 views

### What nations still require Morse code testing for Amateur radio license?

Going a bit further I'll ask, for which licenses (all or just for licenses for HF operation) and at what speed (5 WPM, 10 WPM, none specified)? The reason I ask is because every so often I'll see ...
59 views

### Pondering variations on the vertical bazooka antenna

I've seen these antennas built out of coax that are called a bazooka vertical. It's a kind of 1/4 wave vertical, or perhaps a 1/2 wave dipole. Constructing such an antenna is to roll back the outer ...
121 views

### Why are many ground radials preferable to a single ground stake buried 1m deep?

Surely a 1m copper stake provides better ground connectivity for a vertical dipole?
145 views

### 50Ohm Coax presents 50 Ohms of impedance on which frequency?

Either there's a simple answer that I'm not finding in a spec sheet somewhere, or, I'm asking the wrong question!
78 views

### Frequency synchronization in GNU Radio for OFDM 16-QAM x 6

I am transmitting a 16khz data signal using OFDM 16-QAM x 6 carriers and the library amodem using a HackRF. However, I am having issues receiving this signal as the frequency the HackRF transmits on ...
48 views

### What is “allied mode” with regards to PSK31?

Wikipedia says: Colloquial usage of the term 'PSK31' in amateur radio usually implies the use of the most commonly used variant of PSK31: binary phase shift keying (BPSK). BPSK uses no error control, ...
73 views

Teaching myself 4NEC2 and have most of it under control, which is good. Regarding radials & grounds, i've been learning the "rules" NEC(2) has, summarised below. 4.1. Free space. In the ...
93 views

### Questions about effective isotropic sensitivity(EIS)

Recently, I read something about EIS (effective isotropic sensitivity) and TIS (total isotropic sensitivity). I'm trying to understand the concept, but I find it's quite hard for me. In the book ...
83 views

### How to select capacitor for diplexer use

Follow-up on this question: How to prevent cracking the capacitors in my diplexer? Short story: 2m/70cm diplexer, to be used up to 50W. Schematic from Elsie: S21/S11: I don't know exactly what to ...