Other SOTA sites: SOTAwatch | SOTA Home | Database | Video | Photos | Shop | Mapping | FAQs | Facebook | Contact SOTA

Kits kits! Useful accesories


#1

I’ve been building some kits that I use to carry along with me when actívating for SOTA.
These are unexpensive accessories. It’s a lot satisfactory when you build and test with success such homebrew equipment. I encourage you to consider homebrewing as an interesting part of this hobby, and specially usefull for QRP’ers.
Here below I show some of my finished collection of parts, completed with identification label.

DESCRIPTION

1) EFHW (End Fed Half Wave ant) feeder

There are several designs for a transformer to feed the high impedance resonant half wave End Fed antenna. I use this practical and robust feeder composed of a FT140-43 toroid plus a 150 pF 1kV capacitor.
It is easy to build and it works fine with resonant half wave wires cut to the frequency you want to run. A Multiband End Fed version is feasible adding links or traps to the wire in proper places.

A smaller version with the toroid FT114-43 can be produced for just 5 watt.

2) CW Audio filter (Hi-Per-Mite)

This is an easy entry level kit that reduces the audio bandwidth in the CW section. I own a FT-817 without any filter, and after 100 activation I’ve decided it’s time to reduce my ear stress when I operate CW!
This filter reduces effectively the bandwidth to something around 300 Hz, therefore making possible to work in a frequency without hearing other unwanted stations operating + or – 500 Hz next your frequency.
The kit is provided by the US Four State QRP Group and you just have to solder a few through hole components and add an enclosure. I prepared it as an external accessory that I insert between the rig and the earphones, although it could be integrated inside the rig as well.
Hope to enjoy much more CW on summits from now on.

3) PWR / SWR qrp meter.

This is also an easy kit called NoGaWatt supplied by North Georgia QRP Club in US. It can be built with two meters, but instead, I prepared a compact version to be used with my MTR rig using a single meter and a selector (Forward/ Reflected). I don’t want to fry the finals with a bad antenna setup!.
You see in the picture the dirty component surface mount of this kit that works much better than the typical led light swr indicator.

4) Current Choke

When using non resonant antennas (random wire plus Tuner) I experienced some issues due to RF flowing to the rig. I decided to build a small 1:1 current choke by winding 12 turns of Teflon coax size RG-174 over a Toroid TX310/23/15 material 4C65.

KIT IDENTIFICATION

When you collect a number of kits, and you see all your black boxes around, it’s time to add a label to identify what is what.
I simply print a description and place a transparent label over (cutting out a mobile phone protective film).

Why do I add my callsign there? If I ever forget one of my kits on a summit maybe another activator can locate it and give it back to me! :smile:

I’m considering to add a QR label just in case a non-ham finds it…

If you have any other hombrewed gem at hand, feel free to add a photo and description of yours here below.
Take care, VY 73 de Ignacio


#2

Very interesting Ignacio!

Thanks for posting and sharing your pictures.

The majority of my SOTA equipment is built from kits or home brew. I like to run dipole antennas, I’ve made quite a few of those! I also have the http://www.HamShop.cz end fed tuner kit but I haven’t tried it yet. I built the tuner a few years ago and even prepared the wire elements.

I have three MTRs -

Recently finished is a Small Wonder Labs SW-40+ with keyer, frequency counter and lamp

My summer garden rig SW-20+

LA1KHA PP3 challenge rig

I have several RockMites covering 80/60/40/30/20 and 17m

Then there’s the scratch built DDS BITX20

A great kit which is sadly no longer available is the QRPometer power and VSWR meter. Seen here testing the output of MTR#131 with 2S LiPo supply on 20m.

Kit building is alive and well here!

Not for SOTA, but I’m just in the process of building a SoftRock Ensemble III SDR. It’s part of my plan to work VK0EK in Spring.

73, Colin


#3

Home brew / Kits

Your right, nothing like making something getting it to work and gaining extra result of extra satisfaction. But love these little kits that go into these mint tins always tickle me and I have to admire the work that goes into them.

This no be kit, but could be, me 9:1 Unun sorts out my end fed antennas I have at hand for portable also made me self. That reminds me, one day i will find out what I have done wrong with me speech pro kit.

Karl


#4

Colin

Is the pint also “Home brew”?

Peter
G1FOA


#5

of course :smile:

Thanks Ed for this arrived this morning :heart_eyes:

Looks like i be spreading me wings a bit and going into digital modes and SSTV etc
Looks like a little sweet tin is in order. :smile:

Karl


#6

This one is :blush: :beer:


#7

“A black, dark, mysterious, SOTA IPA”! These India Pale Ales seem to be infinitely transmutable!

Brian


#8

No problems Karl - good luck with building the Digital Interface kit and enjoy the new modes (don’t forget FreeDV HF digital voice as well as all the data modes).

73 Ed.


#9

Hello,

thanks for your comments.
Colin, impressive massive collection of kits… Maybe too many? If you want to get rid of some and make room for new toys, remember me and send me the MTR 5 bands!! No problem with it :smile:

Pete, good deal, but I see a trouble in yours, seems it is a single usage kit…

I forgot to add one more accesory I built.

MIC SPEECH PROCESSOR DYC 8x7

It is also an easy to solder kit. The SMD components are sent preassembled. You have to insert this processor between the stock mic and the FT-817 mic connector. It can be used with the 817, 857 or 897 rigs.

This is supplied by [BOX73][1]. I used it a few times and I got nice reports of improved audio.

There is still one more kit I have although I didn’t build it, a Wilderness SST-30 transceiver. I have to make a photo of it and I’ll post then.

Very 73 de Ignacio
[1]: http://www.box73.com/product/4


#10

Too many kits? No way, that’s impossible!

I haven’t mentioned my Tuna Can collection yet…

:smile_cat:

73, Colin


#11

Nice to see all the stuff brewed. Impressed with the quality of Ignacio & Colin’s work having met both of them and seen their work. Colin’s BITX20 shown @ last GQRP conference was a real piece of art…
Here some of mine…

Acuprobe RF detector
On the shelf for 12+ months…Yet to be finished…

Winkeyer2 Serial
Very useful for those contests…

VK5JST antenna analyser
Invaluable too for the antenna homebrewer…

Genesis G11 SDR QRP - Multiband
The ultimate beast… no other kit have provided me with so many many many hours of enjoyment. My main rig in the shack and contesting rig.

MTR Tribander
only 500gr SOTA stations possible with one of this… good 15hrs of soldering work under the magnifying glass

Portable microwave for the winter bonus

Homebrew dipole centre

Other bits some pieces:

  • Step attenuator from K5BCQ
  • Softrock Lite SDR receiver
  • Betterqrp baluns

Keep on brewing…!

73 de Angel


#12

Agree, but I think at 5 watts, much smaller toroids can be used. For example, for the EFHW I use an FT50-43 without it heating up. For a 1:1 balun, I used an FT80 - KT5X


#13

Hello,
Tuna kits? Do you empty them before assembly or do you keep them filled up as a survival kit?? :yum:

Wow, vy well done Angel, neat solder with your magnifying glass. I’m afraid I’m a bit shaky to enter that level… That microwave aerial is impressive!! A good combination with you cup of tea I guess… :stuck_out_tongue_winking_eye:

Nice to find brewers are still on. VY 73 de Ignacio


#14

(With apologies to the tunefs man pages)

You can tune an antenna but you can’t tuna fish.


#15

Tuna? I hate the stuff, even if the tins were full, I’ll still starve… I don’t like Altoids either :smile:

I’ve actually moved on to pineapple tins, they don’t smell as bad!

I found this in my cupboard - (I wonder how many more rigs are lurking in there? :wink:)

Angel, very good workmanship in your projects!

Andy, Rex sells an ATU, I’ve been tempted but not indulged as yet…

73, Colin


#16

OH wow the tuna tins.
wicked recycling.

Karl


#17

Well, the only 2 kits that I’ve got currently on the go are the KD1JV MBDC.
It’s designed around the cheap AD9850 DDS that you pick up from China for a few pence.
I’m trying to finish this one as we speak. It’s been sitting in my build box for months now!
It will be for Top band and 80m

I’ve also made a start on the EGV-40 Trx. When I say made a start, I’ve soldered in one resistor.
Its a nice kit however and shouldn’t take more than a couple of days to build.

How useful they’ll be for SOTA, I’ve no idea. They will be used however :slight_smile:

Amongst the boxes and boxes of stuff stacked in the corner, I can say that I’ve actually used all the following for SOTA. None of them are kits however. They were all hand rolled (if that wasn’t obvious :grin: )

Memory keyer - vintage 1980. The 1KB (yes really, 1024 bytes) Intersil memory chip in this cost me £16 and nearly bankrupt me for a couple of months! These memory chips supported the Intersil 6100 Processor if anyone remembers them.
Keyer still works fine and is used on rigs with no built in keyer.

Capacitive touch paddles and keyer. (1987)
This was thrown together whilst I awaited delivery of my proper kit to VS6.
Has been used on G/CE-001 to key the Trx below.

300 mw VXO TRX. (1981)
Was used just because I had it. Pictured with prototype preamp. Both now in the scrap box awaiting disposal :smile:

In the same scrap box, a multi band CW/SSB HF Transceiver. (1989)
QRO this one with 25W output.
Did a bit of chasing with this but now consigned to the scrap box.

I daren’t open any of my other boxes…
So much junk!

73
Pete.


#18

Hi,

as promised, I found my last kit. I didn’t build it myself, but it’s a nice TRX:

Widerness SST-30 for 10 MHz, including a 5w PA.

I just added some labels to show functions. It has a wide VXO and half the band is covered.
His selectivity is too narrow, around 150 Hz, difficult to get all stations if you build a decent pile up.
You can not quite well know in advance the frequency you are in. I just used once from a summit and couldn’t log any qso. I must try again somewhen because it’s a nice old kit.

Here for size comparison with the MTR:

VY 73 de Ignacio