Fishing In the Woods: Looking for Radio Signals

This was the first Winter Field Day that justified a reason to purchase an ice fishing tent.

The tent manufacturer claims you can set this up in under a few minutes and pack it up even quicker.  Lets see what the breakdown looks like.

 

Inside the Tent:  Gear needed

We all like lists right?  Here is what was in use in the photo below.

• Icom IC-705

• Emtech ZM-2 Manual QRP Tuner

• Heil HTHD-Y headset

• Lenovo T495 laptop

• 12aH DIY LiPoFe4 battery pack

• Polaroid Brand Travel Tripod

(Photo Courtesy:  Ken Campbell AD2T)

Excluding the table, chair and propane heater, this was a minimal operation which proved pretty comfortable even in the low temperatures during Winter Field Day.

The goal was to operate 10m or 15m  PSK31, JS8CALL or SSTV but most of the time it seemed that FT8 was more popular, so that would not count for Winter Field Day. Too bad!!   The 15m band was wide open which was really nice.  A few contacts were made on 40m SSB, hence the need for the headset.

Antenna Questions

A 40m Off Center Fed home made dipole was used with good success.  This design allows for 40m, 15m and 10m operation without really needing the tuner..  One leg of the dipole is 44 feet and the other is 22ft.  At the center point is a 4:1 DIY balun.  The antenna center was mounting with velcro ties on the 20ft orange Jackite fiberglass mast.   

The mast was secured to the ground with a ground stake and length of PVC pipe which the mast simply slides over.  The longer end of the dipole was attached to a nearby tree with a length of paracord.  The shorter end was attached to an artificial tree known as a tripod.

Even with heavy winds, the antenna system as expected maintained upright for the 24 hour event in the frigid cold!

This antenna system works great and easily stows in a bag designed for audio equipment.  Many other accessories for additional HF and VHF antenna also fit in this bag along with a few 25 and 50 foot RG-8X feedlines. 

I would estimate that my entire antenna kit which includes the storage bag, surplus tripod (RIP KE2EJ), feedlines, support stake, full wave 2m loop, Arrow II antenna, 40m OCF, 10m-17m-20m-30m linked dipole,  End Fed 40m/80 and a few other odds and ends cost less than $200.  This is a lot of antenna gear for different applications mostly meant for POTA operations and not SOTA activity which is much smaller scale.

(Photo Courtesy:  Ken Campbell AD2T)

An article like this can get really long if I wanted to detail how to set up Wi-Fi on the Icom IC-705 to talk to the laptop with virtual com ports and audio cables, but there are great tutorials on YouTube which cover that already.  

The only issue I really ran into which continues to be a level of annoyance is that the "705" has such a broad front end that semi decent antennae can easily overload things, so backing the RF gain down is a good idea.  

Nearby strong out of band signals also are problematic and an external band pass filter will be needed for the 705 to perform better during group special events like Hudson River Radio Relay coming up in June..

Last year during that event, the 705 on the 6m band was useless when nearby 20m or 40m CW and SSB activity was taking place.

Not really sure if this article answered any questions for anyone, but it was fun setting this up for Winter Field Day and spending some time playing radio plus teaching others about how to set up a minimal self contained field station.

Doing "data stuff" over VHF/UHF FM?

First, let me set up a user scenario so this makes sense as to what problem is being solved.  

Imagine you are somewhere where you have a fully charged smartphone, but no network access of any kind along with a dual band handheld amateur radio.  

Aside from the above, you happen to have some type of HF radio with you, but you forgot a few important things at home like a Morse code keyer and some important thing that prevents you from powering your HF radio, like a power cord, fuse, etc. 

Your only method of outside field communications is with your handheld radio now! 

Luckily, you have a few extra things  with you such as an Easy Digi Interface and a USB-C to 3.5mm adapter with you. How can you communicate using non-voice modes?

Sending certain data signals over FM provides some benefit. Lets explore a few of these where you will be connecting your smartphone to your handheld radio.

Smartphone Headset Adapter

If you have a smartphone with a headphone jack, that is great but is feature becoming less common.

The latest Android or Apple devices have done away with the standard 3.5mm headphone jack and is why you need an adapter that goes from USB-C (Or Lightning) to a 3.5mm jack.

For $9.99, this USB to 3.55mm TRRS headphone adapter gadget can be yours and will find many other uses you can think about.  Support fellow Hudson Valley club OMARC by using Amazon Smile.

Easy Digi Interface

This simple box allows you to connect your smartphone to your handheld radio.  You may or may not need the smartphone headset adapter, but lets pretend you do.  

It is now simple for you to connect your radio and smartphone together thanks to KF5INZ and the appropriate version of his adapter for your radio. Below is pictured the version appropriate for the Alinco DJ-MD5XTG DMR radio along with the USB-C to 3.5mm TRRS adapter.

An alternative option, but still using a different form of the Easy Digi Interface was even written up by HVDN's Joe NE2Z back in 2019.

Do Not Leave Home Without Software

Since you do not have network access to download applications on your smartphone in this described scenario, install a few before you get stuck somewhere.  

The first application to focus on is one that you can send pictures with.  SSTV and its different modes offer different benefits and this ability might come in handy to increase situational capabilities.

The second application to focus on is something that can send text data in a conversational format.  Modes like RTTY and PSK31 are great for this as they work just fine being sent over FM.  Small or large amounts of text can be shared with these modes. VARA FM is not a focal point in this article since we are focusing on basic implementation for basic users.

A third application is something where you can share your location and short embedded messages.  APRS.  APRSdroid is a great way to start related to APRS without a dedicated APRS radio. 

Here is the list of essential communications applications you should have on an Android device relative only to the use case described in this article.

Please note that similar versions exist for Apple devices, but HVDN can not provide comment/support on those, but we welcome your Apple favorites. 

Robot36 - Highly Recommended as SSTV reception application because of modes supported like PD50.

SSTV Encoder - Recommended for SSTV transmission via supported modes like PD50

APRSdroid - Highly recommended for sound card based APRS with appropriate interface cable.

droidRTTY - Recommended for RTTY over FM or other modes.

droidPSK - Highly recommended for send/receive of PSK using appropriate interface cable.

droidSSTV - Another SSTV option, but better options exist. 

AndFlmsg - Many supported modes but experience may vary based on your smartphone/tablet.