Homebrew Antenna, a NanoVNA & The Kindness Of Fellow Radio Enthusiasts

Hi All,

Hope you're keeping well and enjoying your radio.  


As some of you may know, I do like a bit of building stuff for my radio interests.

There's always a project on the go, a radio to repair, an electronic construction and more recently I've been enjoying the pleasures of making antennas. I have just built my very first UHF beam from an old TV antenna and considering I had no actual 'test gear' except a CB SWR meter, (for UHF no less - worked well!), and a quickly knocked together 'Field Strength Meter, (which I must now box as it came in very handy!), it all came out rather well.

Now the one thing that has really struck me with those of the radio 'persuasion', (CB'ers, Hams, PMR's, the lot!), is that you can all be a rather generous lot.

Two Ham friends already donated equipment in the form of radios to aid me in my Amateur Radio pursuits. OK, some of it rather old and a few requiring repair and restoration but given in the knowledge that I would be able to fix them up. Which I, (mostly), did!
(I say 'mostly' because I'm still having problems with my old FT757!)


Anyway, after my recent UHF beam project I received a mailing from a fellow Charlie Tango member.....asking for my address(?!?)

.....a few days later this turned up!




Now to say I'm grateful would be an understatement, I literally don't know how to thank them enough!!!
(Still shocked at such generosity.)

I won't name them, unless of course they want to be named but I'll leave that up to them.



Well, with such a piece of kit at hand I quickly learned most of the functionality and re-read what I'd forgotten about 'Smith Charts'.

I just had to build another antenna and I had been thinking about a 2m vertical but with a little more 'oomph' than my first dipole, coax 'Townsman' and a recent J-pole, all of which worked but were rather lacking.

Enter Mr. Peter Parker, (yep, I got the old 'Spidey' thing too), VK3YE an Australian Ham who loves his 'homebrew' projects and I've read stuff from him in old copies of 'Amateur Radio' Australian magazine to watching a lot of his videos. He did a video a while back on an 'Extended Double Zepp' for 2m so I had to give it a go.



Great stuff eh?

I didn't have any more old TV antenna bits but I did scrounge together some old garden canes, (lashed together to make the required length), some speaker wire and some more RG6 coax, (yes I know it's 75 ohms....still works as you'll see).

Now unfortunately I don't have any pictures of this lash-up tied together with more lengths of green insulating tape than you can shake a garden stick at.......because I sent my wife up into the loft to install it as a more or less 'willing' volunteer! (Had to get in quick when she said 'yes' to my request - Love her! )

If I can persuade her up there again I'll get some pictures of the monstrosity antenna which only just fit the height of the loft space.

In the mean time the ever so flipping helpful NanoVNA did a grand job of showing me readings whilst I shouted up to the loft space, "Clip another half inch!" to my fantastic missus. (She must be fantastic to put up with my nonsense!)

And here were the results.....



Yeah, sorry for the blurry picture but I was wetting myself like an excited puppy at having this wonderful piece of kit.
(Plus I still haven't figured out how to get the capture software working on Linux yet!)

Not too shabby though I think you'll agree.

(That SWR dip looks big but it was 1:1.01 at the centre and less than 1:1.4 at the band edges!)


It's all working rather well, definitely receives & transmits better and considering it's a bunch of scrounged together stuff I'm rather pleased.


So with all that....

     Don't be afraid of building stuff even if you've only got what appears to be a pile of cr*p because you can often turn it into wonderful radio
     goodies, (without buckling the credit card!)

     Don't be afraid to ask your 'better half' if they would mind helping you out, (the worst they can say is 'No').

     Don't refuse a gift, you'll only offend their good intentions.

...and never be surprised at the generosity of fellow radio enthusiasts. Just be grateful.


A big thanks to you if you've read through more of my waffle and a HUGE thanks to the wonderful Charlie Tango member that sent me such a wonderful gift.


All my very best to you,
Victor

Victor wrote:

     Don't be afraid of building stuff even if you've only got what appears to be a pile of cr*p because you can often turn it into wonderful radio
     goodies, (without buckling the credit card!)

✓ I second that, even if the wonderful radio goodies you've created still look like a pile of cr*p when you’ve finished.. on more than one occasion I have had "Is that safe?" or "Shouldn't that be in a metal box?" from my wife or sons.

Quote :

     Don't be afraid to ask your 'better half' if they would mind helping you out, (the worst they can say is 'No').

✓ Though mine has always said "No". She has never once entered the loft. Not even a foot on the first rung of the ladder. More than helpful for other requests though, she's just not going to go up there.

Quote :

     Don't refuse a gift, you'll only offend their good intentions.

✓ If anyone has a spare Icom IC-7851 they are they are throwing away I wouldn't say no

Joking aside, there's a lot of good people out there in the world and from what I have seen since joining CT a lot of those people appear to be members here.

It looks like a great piece of kit that not only have you made good use of already, but I'm sure you will continue to make use of often in the future. I think at some point I will look to get something similar to help me understand better why some of what I have put together actually works. Honestly, sometimes antennas just work when they really shouldn't and I don’t know why.

Look forward to reading about more of your antenna experiments in the future.

Hi Neal,

Cheers for your response it really is appreciated.  


I agree, you can take a pile of cr*p, turn it into something wonderful for radio and it doesn't matter if it still looks like cr*p so long as it works!
(I've never got why you'd shell out for a piece of wire with a fancy name anyway!?!?)

My missus wouldn't have ever gone into the loft at one time but because of my leg she does do her very best to help out wherever she can bless her. Not only do I love her but damn well appreciate her too.

There are a lot of good people out there Neal, it's always a pleasure and a joy to come across such individuals. Like you say there's some great folks here at Charlie Tango who at the simplest will happily give just their time to help others out. You can't put a price on something like that.


The NanoVNA is a fantastic bit of kit and you wouldn't believe how unbelievably grateful I am to be gifted it. I've only scratched the surface but considering it's not an expensive lab VNA it does have some useful functionality. The Time Domain Reflectometry is something I'll be investigating next and a host of other things.
(I've got to admit, it don't half make antenna construction much easier that's for sure! )


Again, much appreciated mate.


All the best to you,
Victor

Great write up Victor, those NanoVNA are so good for the price but as a gift, well. Thank you to the Member who sent that to Victor, it is guaranteed a good life with him, lol. 

Great stuff all round everyone.

Never did figger out how they worked the NanoVNA things that is lol.
Glad your having fun Victor but i think you will need a bigger loft very soon.
Linda would tell me to naff off or words to that effect if i asked her to go in the loft "SPIDERS".
She will help if i ask but no way in the loft.
Have fun with your new kit m8.

Hi Paddy,

As always, much appreciated mate.  

They are a great bit of kit and it's an absolute pleasure to have been gifted one. It definitely has a good new home!


All the best,
Victor

Hi Alan,

Took some head scratching, reading plus watching some videos and a play around to get to grips with it. Phenomenal bit of technology and despite it's diminutive size the old bear paws and bats eyes cope well.

We have an invasion of Pholcus phalangioides or Long Legged Cellar Spider, (so WTF are they up there? Ha! Ha!), in our loft but Teresa did do rather well up there. I'd love nothing better than to install a lift arrangement so that I can get up there, clear the space and build an awesome antenna farm!!

Definitely having fun with it Alan mate, fantastic bit of kit.


All the best and send my regards to Linda,
Victor

I was going to say I bought a Kindle book on how to do the basics with the NanoVNA only 80 pages for £2.28.

Great suggestion there Paddy.

Victor wrote:

Great suggestion there Paddy.

I was trying to convert the book to PDF yesterday Victor without much success I might add. I’ll keep trying though.

Hi Victor.  Great post and informative thanks.  I wondered if you would be kind enough to do a video on basic setup for swr.

I have just bought one looked at loads of videos but one from a fellow member would be great.
Thanks Tony 3907

Hi Tony,

Thanks very much.


I'm afraid I've got to admit..........I've never made a video in my life. Honestly, not once! 

The mobile phone I was given takes very good photos but I've never used the video function at all. The damn thing is the size of a briefcase so I rarely even carry it with me much to the annoyance of family members who state that they've either called me, sent a text or some apparently funny video.

So I'll have to apologise and state that a video from me probably isn't going to happen.


If anything I found the written documentation for the NanoVNA much more useful than a video anyway, but I prefer reading. The problem with a video and something I've stated before is the "monkey-see, monkey-do" methodology in that you are just copying what someone else is doing rather than learning what you are actually doing.

For example, you can measure the frequency sweep and SWR readings with a NanoVNA but it doesn't tell you the whole story with the antenna you are testing. You'll also have to check your return loss and probably the feeder, (coax), for any losses with it to get a better idea of the whole antenna system and even then you won't know the real performance of the antenna. Despite making some fantastic readings with the NanoVNA and it making the task of 'tuning' an antenna to resonance much easier it doesn't tell you much else.......

I still use my knocked together field strength meter to check the real world radio emanations from the antenna to see if it will actually work and then check it's performance on air.

A 'gamma-match' antenna can be adjusted to give good SWR readings as can tuning an adjustable 'whip', but a field strength reading will give you a better picture. (There was a time when 'good' SWR meters actually had a field strength option built in.)

I've said before, a dummy load gives fantastic SWR readings right across all the frequencies but doesn't make for a very good antenna!


So again, my apologies......I can't make videos and unfortunately I have a heck of a time simplifying something that's actually way more complicated than at first seems. SWR isn't everything.


I know, not much help from someone who usually goes out of their way to be helpful.


Keep at it though, there is some good material out there to help you use a NanoVNA but remember.......you can read and watch a hundred videos on how to drive a car, but you actually have to sit in the drivers seat and 'drive' it to get anywhere.  


All the best,
Victor


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The NanoVNA has much more going for it than simple SWR measurements.

So far I have also used it to -

     Measure multiple readings for homebrew antenna construction.

     Measure and identify a batch of old radio crystals.

     Test a homebrew 2m/70cm 'splitter' for an experimental dual band antenna.

     Provide an RF source in 'CW mode' for testing and peaking a receivers front end.

     .....and probably a few other things I've already forgot.


But can I make a video? I wouldn't know the first thing of how or where to upload it!


The NanoVNA is a really good tool but just like how you could never repair a whole car with just an adjustable spanner, it's only one more useful tool for the RF/Radio tool box.

Many thanks Victor. No problem i understand re video making.  I'm useless I'm afraid.  I managed to calibrate the VNA that's a bonus since having 2 heart attacks and 2 strokes my grey matter is now shrivelled grey matter.  The easiest of things become very difficult.  I was going to buy an antenna analyser but saw what the vna did so it was the cheaper option. 
I will have to have a look at the amazon kindle book on vna i think i can afford a couple of quid.
Anyway Victor keep up the excellent work and a big THANKYOU for all your efforts.
73 Tony 3407 (M0MTD)

No worries Tony mate.

I'll have to agree that despite the learning curve the NanoVNA is an awesome piece of kit and I'm so lucky and grateful to have been gifted it. I had an antenna analyser lent to me, the MFJ-259B, and despite the horrendous price of such items it doesn't do half of what the NanoVNA does!

Yeah, Paddy's suggestion of the Kindle book sounds great.


All the best to you there Tony and I hope you get on well with your VNA.

You never know, you might be able to teach a few of us old dogs some new tricks with it.



Best Regards,
Victor

Hello Victor ,great post ,as i am new to the forum ,i thankyou very  much for your welcome message ,on the nanovna ,i have some good video links ,very  explanatory for begginners , i will post them tomorrow as i have them on external hard drive , the nano for me was extremely useful for making and tuning my homemade gain master 5/8 on 27,160mhz ,return loss of 46 DB and a VSWR of 1,04 to 1 , please forgive me if my english grammar is wrong sometimes as i live in Italy for the past 40 odd years ,as i was born in RSA and my parents left and went back to Italy when i was 16 ,so i will post some good links tomorrow, 73s to all nik555

Hi Nik,

Sounds great.  


Anything that helps each other out is all good in my book. I look forward to any videos you have.

No need for any apologies regards your English skills, I think you do very well.


Il tuo Inglese è migliore del mio Italiano.



73's
Victor

Hi Victor ,i could not find all the links ,but only a few ,have to check the pendrive if i can sttill find it,on it was some realy good links ,on measuring inductance of coils and other , here below are 2 pdf links which are a must for those who are starting and 2 good videos ,

SORRY forum rules say i cant post external links for 7days ,we will have to wait
73s to all ,nik555

No worries Nik.

Look forward to seeing what you have and thanks again for your input to the forum, much appreciated.  


All the best,
Victor

Victor wrote:

I'll have to agree that despite the learning curve the NanoVNA is an awesome piece of kit and I'm so lucky and grateful to have been gifted it. I had an antenna analyser lent to me, the MFJ-259B, and despite the horrendous price of such items it doesn't do half of what the NanoVNA does!

I've had a 259B for years, and despite having a couple of VNA's and one or two other newer analysers, I still grab the MFJ for a quick check of resonance or SWR.  It's just faster to use and gives enough info for most jobs.

Fair point there Jeff and up to now the MFJ-259B I was loaned has done a grand job.
Runs out of steam at 170MHz though so wasn't able to help me with my recent 70cm antennas.

They still hold their price second hand too, here in the UK they go for about £200 - £250.

Got to admit though I am loving the NanoVNA - recently used it to identify some odd crystals, setup the front end filter on my old FT227RA and used it to build a recent VHF/UHF diplexer.

Victor wrote:

Fair point there Jeff and up to now the MFJ-259B I was loaned has done a grand job.
Runs out of steam at 170MHz though so wasn't able to help me with my recent 70cm antennas.

They still hold their price second hand too, here in the UK they go for about £200 - £250.

They do a later model that does UHF, but for the higher frequencies, I just use the VNA…..rarely need more than HF, TBH as that’s where I do most of my playing.

Mind you, if they sell for that much, I should get rid of it and put the money towards a RigExpert I’ve been eyeing up, as they combine the best bits of the MFJ and the NanoVNA.

Once I’d learnt to read one, the Smith chart display is very handy for working out what’s going on, and that’s one area the MFJ falls down.

hi to all ,2 pdf files on nanovna basics, aand a good  ytube video link, still cant find the other links but got to check my other external hard disk ,
2 good pdf docs to read
https://www.bwcelectronics.com/articles/NanoVNA%20User%20Guide.pdf

https://qsl.net/g0ftd/other/nano-vna-original/docs/NanoVNA%20User%20Guide-English-reformat-Oct-2-19.pdf

One of the best vids ,a bit long but excellent.
https://youtu.be/mKi6s3WvBAM

nanovna basics
https://youtu.be/QJYeFpiqY8c

https://youtu.be/totwu4IbavE DONT DAMAGE YOUR NANOVNA
Victor can you tell me how to measure crystals i have a lot in my junk box
73s to all .nik555

Great stuff there Nik.  

I'm only on my tablet at the moment but when I get the time on my PC I'll do my best to make up a posting for you with your helpful links. (Make it easier for others to find and ensure you get credit.)


There's a good video available on the following link to get going on crystal testing :-

https://www.youtube.com/watch?v=rVIHVi-7brs


You'll have to watch out for faulty crystals as you won't get the results you expect but that's great for identifying such. 
There is more in depth information out there but mostly in a written form and it depends on how far you want to go, I just needed basic identification.


All the best,
Victor

Victor thankyou , just have check the frequencies ,as i want to build a small 14mhz RX just to add to my goodies , as my frequency counter has gone wrong ,and i also  have to change the LCD of my oscilloscope , 73s to all .nik