Set realistic expectations

First, keep in mind that technology has it’s limits. It’s unlikely using a handheld radio and a stock antenna, for instance, you will be able to talk across the state without using repeaters and other services offered by HAM radio clubs you may need to join. VHF and UHF are limited by line of sight. That is why tall towers exist, because the further you can “see” the further the radio signals go. It’s important to understand what the technology can and cannot do, and I hope to explain that below.

What sort of communication do you plan to do

What this question means, is are you looking to communicate across town, or around a small geographic area (like within a park)? Who do you plan to communicate with? A radio is only one piece of the puzzle, there needs to be someone within range on the other end who you wish to talk to. Are you okay with analog radio which is easily eavesdropped, or do you want the added complexity of digital radio (such as YSF or DMR) which although unencrypted has a higher barrier of entry for snooping? What is your budget? $100 or $1000? Do you plan to communicate directly radio-to-radio (known as simplex) or do you want to use a repeater as an intermediary?

With those questions out of the way let’s talk about some of the technologies:

Base Stations

Base stations are very useful for communicating across town or even within the county. They will be permanently setup in a home, garage, or office. Usually they are connected to an antenna mounted on either a tower, or at least a rooftop so that it has some height. Remember the higher the antenna the further you will be able to communicate. Additional height is almost always more important than additional power. Base stations are made up of a “mobile” radio (designed for a vehicle) attached to a 12v power supply that plugs into AC. Some people also add a 12v deep cycle battery for off grid use. Base stations realistically can talk within a 5-10 mile area directly (simplex) if both base stations have elevated external antennas. Base stations can talk much further when using a repeater, it’s not uncommon to be able to use repeaters 30-50 miles away. (I can access repeaters in Waterloo and Muscatine from my home by the airport)

Mobile Stations

Mobile stations also are useful for communicating across town or within the county. But, mobile stations usually are limited to the largest range when communicating via repeaters only. Without a repeater, realistically you might expect to talk to a base station 5-10 miles away, but another mobile station only within a few miles. When using a repeater, you can likely make it to repeaters within 20-30 miles of you and then talk to other stations within the repeaters coverage area. Mobile stations use the same radio as base stations, and are attached to the vehicle battery which makes then disaster ready.

Handheld Stations

Handheld stations, or walkie-talkies, are many people’s first entry into HAM radio. They can be very useful, because they are entirely self contained and highly portable. Many people add additional features to their handheld, such as external antenna, power supplies, speaker mics or amplifiers. People even use handheld stations as base stations. When in their basic state (internal battery and internal antenna) a handheld may communicate short distances directly to other handhelds. They can communicate further with base stations, but usually you are still limited to a few miles under the best of conditions. When using a repeater, a handheld can talk to anyone within the repeaters coverage area, so probably 20-30 miles.

Repeaters

It might be a good time to discuss the benefits and draw backs of using repeaters. Repeaters are basically ham radio base stations located at tall towers (or sometimes people’s home) that act as a retransmission point. They receive a signal and then retransmit it at a much higher power from a much taller antenna. This means that anyone within a repeater’s service area can communicate with anyone else within the repeaters service area — for instance two handheld radios can communicate even if they’re 20 miles apart as long as they’re both in the repeaters service area.

Why wouldn’t you want to use a repeater then? Well, there are some drawbacks. First, they are a limited quantity, for instance there are about 5 reliable and wide area repeaters in Cedar Rapids. It’s possible (but somewhat unlikely) they could be tied up when you want to use them. Additionally, if one is tied up, both stations need to know which other repeater to try and in what order such that they can still meet up on the air. Also the repeaters are owned by individuals, or in some cases clubs, who pay to keep them operational. So you may need to join the club to use them.

Secondly, repeaters are great when things are going well. But not all repeaters are available if the power is out. Some repeaters have battery backup, but that will only last a few hours or days at most. And if the tower was to collapse, then the repeater would also be offline. Depending on a repeater in a disaster situation could be a bad bet!

Finally it’s also important to consider that repeaters are a well known frequency with hundreds maybe even thousands of people listening at any given time. The repeater 146.745 in Cedar Rapids is the most well known repeater in Eastern Iowa. This isn’t a big deal if you’re just meeting for lunch chat — but if you’re discussing anything private then forget about privacy.

Digital vs Analog

For the last 60+ years, most two way radios were analog. This is a very simple technology, it’s readily available, and it’s cheap to produce. You can buy an analog handheld HAM radio for < $40.

However analog has some disadvantages. It suffers from noise where the weaker the signal the more background static/hiss will be present. This can make it difficult to hear or understand when signals are weak. It’s easily listened to, with other ham radios or with scanners. It’s limited to one conversation on a frequency at the same time, since only one radio can transmit on a frequency. It’s relatively power hungry on handheld radios since it transmits 100% of the time you are talking. There are other drawbacks as well, but those are the ones most users see.

Around 10 years ago, many commercial and HAM operators started moving to digital. There are 4 main types of digital ham radios in use today. YSF (also known as C4FM) is Yeasu’s standard. DV short for Digital Voice is ICOM’s standard. DMR is an open standard made by many manufacturers and Chinese clones (also known as MOTOtrbo which is Motorola’s patented version). And finally there’s P25 which is another Motorola proprietary standard which is commonly used in the commercial space by law enforcement.

Each of these standards has different advantages and disadvantages. And the big disadvantage is that none of them are compatible with each other! Some advantages are that digital modes can have much clearer audio, much lower power usage, and provide some privacy because the cost of entry is higher. Privacy shouldn’t be confused with encryption however, because anyone with the knowledge can decode these standards when used by HAM radio operators because encryption is forbidden.

DMR – The cheapest digital standard to get into, which makes it the most widely adopted, but complicated to set up
DV – ICOM standard which is getting older so there is some used equipment on the market
YSF – Relatively new standard but if you are a Yeasu guy this is what you’ll be using. Easy to program.
P25 – Lots of off lease and retired Motorola radios on ebay you can get to operate this

Personally, I have DMR, and YSF radios.

Build Ideas – Base Station

Good: Total price from Amazon = $242.23

This is a good entry level setup. The radio, while a “Chinese” clone is a brand that is known to have fairly good support and is robust and well liked by ham radio operators. However, one draw back is it’s relatively complex to use. A printed guide can help with that. The base antennas is modest, and would be the first thing I would consider upgrading to a diamond brand. The feed line, RG-8x has some loss, which means the power is being dissipated in the wire and not making it up to the antenna.



Better: Total price from Amazon = $676.56

This is a nice mid range setup. The Yeasu is a Japanese made name brand radio that has a working lifespan of decades. It is easier to use with more basic functionality and buttons you do not need to dive through menus to access. The antenna has more “gain” which means it focuses power toward the horizon instead of sending it to space. The coax is better shielded which means less power is lost.

Telnet made up almost half of these connections, with 99,840.  Followed by SSH (60,964 connections) and VNC with  52,942 connections.  We only saw about 600 HTTP/HTTPS connections, 20 FTP connections, and 10 SOCKS5 connections.

Some interesting statistics were able to be developed based on this.  Keep in mind, the device  never sent a single unsolicited packet outbound.  All of this traffic was scanning for the device.

Also, you can download the full list of username and passwords or the list of attack source IPs to see every password I saw or everyone who tried to attack.

Check this list, if any of your passwords are on it, change them!!

LAST UPDATED SEPT 23, 2018

Download Iowa DMR GD-77 v2018-09-23

Please keep these oddities in mind when using:

The GD-77 requires the current talkgroup ID to be present in the RX group, even for the channel you are currently tuned to.  This behavior is different than the MD380 which will always play audio for the talkgroup programmed in the current channel.  To avoid having to create dozens of rx groups, my codeplug is configured with the following groups:

1. Brandmeister TS1
   1. 31190 Chat
   2. 31191 Des Moines
   3. 31192 Waterloo
   4. 31193 NW Iowa
   5. 31194 SW Iowa
   6. 31195 SE Iowa
   7. 31196 Cedar Rapids
   8. 9 Local
   9. 3100 US
   10. 310 TAC
   11. 31199 DMX NWS
   12. 31198 DVN NWS
   13. 31691 WI-IA-IL
2. Brandmeister TS2
   1. 3119 (IA3119)

This means that by default when using this codeplug, you will sometimes hear traffic for another talkgroup that is on the same timeslot.  The GD-77 does not change it’s assigned talkgroup while this is happening. For example: If you’re tuned to talkgroup 31196 ON time-slot 1 and hear traffic for TG 31199 you wish to respond to, you need to change channels to a channel configured as talkgroup 31199 before you can respond on talkgroup 31199.

Also keep in mind I have not created separate rx groups for each repeaters ‘local’ talkgroup, so you should manually do this is use of those talkgroups appeals to you.

Power save options have been disabled to improve RX preformance.

Radio configuration has been changed to allow 2 additional TX attempts to reach repeater as this is misconfigured in stock codeplug.

Please contact me with any changes, errors, or problems, dmr@shawngarringer.org

To follow along, please download the following file: Example Worksheet

Anyone operating a DMR GD77 radio in Cedar Rapids or Iowa City may find the following codeplug handy.

This codeplug is based on the very hard work of the Iowa DMR Group.  I have attempted to duplicate the MD380 codeplug for the GD-77

Please Note: I have not added the talkgroups to the RX Group List so you will need to enable Monitor mode on your radio each time you power it on to properly hear DMR calls.  In Monitor mode (sometimes called promiscuous mode) you will hear any calls for any talkgroup on the timeslot you are connected to.  This is useful as you can easily hear if the timeslot is in use before interrupting a QSO.  The monitor function can be activated by a long press of SK1 (the key directly below the PTT) and must be turned on each time the radio is powered on (it is not stored in the radio)

This codeplug Requires Radioddity v2.0.5 programming software and radio firmware v3.0.6!!  Tools can be downloaded HERE from my site however if you are untrusting you should download directly from Radioddity’s facebook.

Remember to update your Radio Name to your callsign (purely cosmetic) and your Radio ID to your DMR-MARC assigned ID under General Settings

v0.5 – Zones:

1. Waterloo Metro
2. Cedar Rapids Metro
3. Des Moines Metro
4. Cedar Rapids W0GQ
5. HS1 441.1
6. HS2 441.2
7. Iowa City K0GH
8. DMR Simplex
9. HS2 AK to IL
10. HS2 IN to NH
11. HS2 NJ to VT
12. HS2 WA to WV

Download CedarRapids GD77 Codeplug

When I tore my TV apart I found my capacitor was surface mount, versus the through-hole I saw discussed elsewhere.

First I used my soldering iron to remove the old surface mount.  It was somewhat difficult to heat it up, due to the large PCB.Then I bent the legs of an appropriate through-hole capacitor and installed it in it’s place.

The TV powered on and I am running a burn in test to make sure it runs for several hours…

Yes, this is a 10+ year old TV.  I hope I get a few more years out of it.  Although it has some quirks it’s a nice set and has been a trooper.

I used as the foundation the code plug available at the Chicago DMR group homepage: http://chicagoland-cc.org/

Then I modified the codeplug to replace the WI talkgroup with Iowa 3119 on all zones.

You can download my modified codeplug here: MD380 030317 All

Thanks to chicagoland control center (DMR group) for their awesome codeplug.

https://pgp.mit.edu/pks/lookup?op=get&search=0xE5CC735EFDD5A05B

I created the following BASH script which can do this work.

Google Vault seems to limit you to 15 running export functions at once, so you still have to chunk this up.

First using something like Fiddler or Burp Suite, capture the cookie for your Google session, and the GUID for the matter you want to export the data from.

Then create vault_users.csv which contains each email address you want to export on a single line:

testemail1@google.com
testemail2@google.com
testemail3@google.com


Place this in the same folder as runme.sh

Check out the code here: https://github.com/planetcr/vaultbash/

Working with the fine folks over at Lets Encrypt I have now deployed SSL/TLS security on this website.

I have also worked hard to enable the highest level of security on the nginx (web server) back end hosting this site, and am happy to say that the site has an A+ rating from Qualys.  Rest assured that the data between this server and your web browser cannot be intercepted or modified in any way.

In the future Google will weigh SSL/TLS enabled websites higher in search results, so the time is now to secure your sites!