KC3LUM

Oh fun! Wish I had more free time to lend a hand. Clocks are very interesting devices. 

On 3/6/2020 at 4:57 AM, K3MRI said:

But we never shut anything down for the flu and yet every year thousands, tens of thousands in the US and Canada, die.

I just googled this and sadly tens of thousands do die each year from the flu. I was hoping this was an exaggeration.. 

I watched this interesting video on measuring the harmonics that are generated in Baofeng radios.

I understand why it is important to keep the harmonics within regulated specifications, but as I watched how the measurements were taken I cant help but feel like the antenna is an important part of the equation. If your antenna is not resonate at the frequencies the energy is not radiated (or at least radiated significantly lower). It would be much more convincing to me if the testing took into account the voltage standing wave ratio (VSWR) measurement on the antenna and then did the math to estimate the actual radiated energy from the radio.

If you look at the whole system at the end of the day, the antenna is also a filter...

On 11/3/2019 at 7:23 AM, K3MRI said:

For starters, it rained, rained, rained.

Yes there was no shortage of water!!

Haha I like it! The linear actuator is installed very nicely. What type of connectors are those? I would hate to imagine they are RCA plugs.. the only quick disconnect RF connectors I can think of off the top of my head are MMC which are small. 

I am participating! This will be my first year and I am very excited. I have already participated in 4 smaller race events. It is a great way to get out and use your skills to help. 

Why did the Op-Amp cross the road?

Because he kept receiving negative feedback... 

(might be more of an EE joke...)

VSWR [pronounced by many as 'viz-rar']  is the Voltage Standing Wave Ratio in an RF system. I have commonly seen this measurement called S-W-R in the HAM community, which is not "wrong" but it is like saying dB instead of dBm when talking about RF power measurements. When you say SWR you could be talking about the ratio of standing waves in a kiddy pool or even the ocean. Luckely no one actually pays attention to the waves in the pool, and all HAMs know what you mean by SWR.

I want to take a moment to talk about VSWR and its significance to the community.

First we need to start with Impedance. Impedance is the opposition to current flow in a system and is measured in Ohms. If you have wondered why co-ax cable is spec'ed at 50ohms, it is to maintain the same network impedance. Your transceiver is expecting a  50ohm network. 50ohm is set as the standard.. except for 75ohm networks like your cable tv and most satellite equipment. When your network is all balanced you achieve a near perfect energy transfer. In the real world this is never achieved mostly due to antennas, but we will get to that in a minute. If you have ever tried to connect your radio to an antenna using RG-11 (cable tv coax) from home depot you would have noticed desegregated transmissions, this is because RG-11 is build for a 75ohm network. You can imagine your coax as a network of inductors in series and capacitors in parallel to ground. The inductance changes with the length of the cable and the capacitance changes with the space between the center conductor and the shield. If the coax is installed properly, and the connectors have the proper impedance characteristics as well, then the transmission line will be very close to 50ohms.

Antennas are where the impedance mostly gets fooled with. You will see that antennas are marketed for certain frequency bands, this is because they have an impedance of close to 50ohms at those bands. I have little idea how the wizards that do antenna design are able to make that magic, but there is definitely an art to it. You may be able to receive a wide range of frequencies from a given antenna, but if you transmit with a frequency that is outside of the band the antenna was designed for then the impedance would be to high and you could blow up the amplifier on your transceiver. 

What do the numbers mean? In a perfect world you would have a VSWR of 1:1, meaning the network is perfect and all the energy you transmit to the antenna would be radiated from the antenna. Unfortunately we live in the real world and you will see values more along the lines of 1.4:1 to 2:1 meaning that you are missing out on 2.8% to 11% getting to your antenna.

Here is a video of standing waves in a pool of water 

here is a video of standing waves on a plate 

and here is a video on RF standing waves 

Does anyone have experience with AMSAT, or operating on the satellites? I have recently started the process to volunteer with AMSAT to lend my skills with the community. I am very excited!! I havent heard many HAMs talk about satellite work or AMSAT so I am curious if many HAMs "work the birds" or not.

As a new HAM with only my Tech license (so far), I have been very interested in what repeater setups look like in the real world. Do clubs set up systems with two transceivers and a diplexer or is it all in one transceiver? Is it just an expensive transceiver and a "heap" of parts donated by club members? What is the deal with "System Fusion" and "D-star"?

Please post your clubs setup so we can discuss and learn about the different aspects of the set ups. 

Pictures would be great too! 

Last weekend I made my first HF contacts on the #CherryTreeNet @ 3.920Mhz I had so much fun! Thank you to @K3MRI for letting me operate on his mobile deploy rig, and thank you so much to @K4RT and @wb4kfo for sending my these nice post cards! It looks like I am going to need to order my own custom cards to send back. I realize this is a normal custom for HAMs to send these cards, but being a new HAM I somehow never expected to be lucky enough to get one! 

My Lovely wife, "Babe, you got fan mail from your radio people!"

I am glad that CW was not part of the test because I would not have had the time to venture into this culture if I had to learn CW first. Being able to get my license with not much effort allowed me to gain the desire to learn CW organically. (still haven’t started learning yet but I plan to)

Interesting, thank you guys for your input! It is very helpful to know that many HAMs are monitoring 146.52Mhz, I am ordering a Bumper sticker lol.

After doing some digging I found ARRL's band plan page : http://www.arrl.org/band-plan  

When I got my license I was handed the ARRL chart that shows the frequencies that I was allowed to broadcast on, but I think the band plan guide would have been much more helpful.

@KB7THL, thanks for the tip on the software. I will definitely look into it more. Do you have to buy a separate software package for each radio? The website makes it seem that way.

@K3MRI, I am very interested to see your kit and learning more about HF. Soon I will get my General license so I can broadcast on it.

So as a new HAM I have been trying to figure out what is out there and what works for me. Currently I haven’t ventured out past using local repeaters, but I have found this seemingly simple avenue very cumbersome and not strait forward.

I am curious to hear what the seasoned HAMs do when they travel. Does anyone commonly use technologies like D-Star, System Fusion, and WIRES?

Here is my experience:

To start, I have an 8 Watt Baofeng HT and a 50 Watt Yeasu Mobile. I read the manuals and know how to hand jam the freqs in, but this process reminds me of trying to set a VCR to record something a few days in the future.. a process that is doable but very few people take the time to figure out how to do it, and if you haven’t done it in a few months you are probably going to do it wrong a few times before you get it right. So I bought a programming cable and downloaded CHIRP. I pulled the freqs of bunch of repeaters in my area and dumped them into CHIRP and onto the radio. So now I have a HT with a bunch of local repeaters saved, but I have no idea where 99% of them are physically located. When I am out and about and feel courageous enough to broadcast, I have to pull up my RepeaterBook app, find the repeater call sign close to me, and then scroll through my HT’s memory bank to find the corresponding slot.

Does everyone do this? Because it feels very convoluted.

This process has left me really only tuning to the repeater closest to my house. 

Now I am traveling on vacation and trying to make contact on the local repeaters, so I brought my HT. When I am able to broadcast I have to look up repeaters on RepeaterBook, hand jam them into the radio and kachunk the radio (with proper identification) to see if I put the info in correctly or if the repeater is even operational. I am of course not even saving these channels into the HT because it is a pain and I can’t even give them a proper name, so if I want to go back to try the freq again I might have to re-look it up and of course rejam it in the radio. 

I do not have my mobile radio with me, but hand jamming info into it is just as annoying as the HT. 

I want to know what the “Elmers” do because there must be a better way..