Gizmotchy Antenna Review

[SMILEX2692002]

I purchased a G21. I found the manual to a bit lacking. Having said that I learned from a few mistakes I made while assembling it. If the manual were more descriptive the mistakes would not have been made. A few Facebook Messenger chats with Gizmotchy and I figured out what I did wrong and what needed to be done.
At least Gizmotchy will help via text or they tell you to call them on the phone.

 

[CW61]

Hello,

i bought the G31 and after that i bought 2 additional boosters.

So i have a G51

But: I try to make the setup but i did not get really good SWRs.

I need help

Is there anyone who can give me the working lenghts of the elements and spacings please? Center frequenz should be 27.135 MHz.

Thank you

 

[Marconi]

Hello,

i bought the G31 and after that i bought 2 additional boosters.

So i have a G51

But: I try to make the setup but i did not get really good SWRs.

I need help

Is there anyone who can give me the working lenghts of the elements and spacings please? Center frequenz should be 27.135 MHz.

Thank you

Welcome to the forum.

As I've been told, the GizM antenna spacing and boom lengths are fixed as to construction using screws in the boom and the elements. So, I would guess the add-on booster is also fixed. Not sure about any of this, but the instructions look minimal to me.

I also have a notion the tapered radiating elements are secured using screws, which also suggest to me the whole antenna is fixed as to construction. Let me know if I'm wrong here, OK?

Could you give us some more information as to the details for what you've done so far? Got any good pictures?

1. Did you start off by setting-up your 3 element antenna version with a good match per the specs provided...without regard to your choice of center frequency? This question is just to see if the antenna ever worked right for you per instructions.

Either way you did it, do you know what your <2.00:1 SWR bandwidth (BW) is/was?

My knowing your BW with a good tune can help me determine the accuracy for my model of the GizM compared to your real results.

2. Or, did you just start off modifying the element length or spacing for the frequency you mentioned in your post above?

3. Are you using an antenna analyzer or an SWR meter to tune?

4. Are you tuning the antenna on a temporary mount low to the ground?

 

[Unit 75]

Adjust your gamma for the lowest SWR obtainable on your desired frequency. Write down what the SWR reading was. Once that is done, you will need to adjust the DRIVEN element. Start by lengthening it by 1". Then check your SWR and see if the reading is higher or lower than what you had written down. If it is higher then you need to go the other way and shorten it. Use this procedure for both polarities but adjust one polarity at a time until you get a good SWR reading then move to the next polarity.

 

[CW61]

Thank you Marconi and Unit75

What i did:

I just made the setup for the Driven Element and reached an SWR of 1:1.0 at 27 MHz- as desired @ 15 feed above ground.
Everything looks fine. The <2.00:1 SWR bandwidth (BW) is about 1 MHz (27 MHz +- 500 kHz)
Then i put on the Reflector Element: The frequenz of lowest SWR decreases to 26.4 MHz. It try to fix this with the gamma match but no chance.
Okay i put on the 1. Director Element bt frequenz of minimum SWR decreases to 26.2 MHz (all SWRs are measured at 15 feed above ground).

I am wondering what may be the right way to get the frequency up to 27 MHz again?
changing the length of the Reflector/Director? Or on the Driven Element?
The thing is: SWR changes in height change .-(

I own an RIG55 to make the measurements.https://rigexpert.com/products/antenna-analyzers/aa-55-zoom/

Today i will try this:

(sorry for the length in cm/m: i live in Europe ;-) )

 

[Unit 75]

From reading your above post, the driven element is too long. Remember, the higher the frequency, the shorter the antenna. Also remember that all adustments are done with the antenna completely assembled

I just made the setup for the Driven Element and reached an SWR of 1:1.0 at 27 MHz- as desired @ 15 feed above ground.
Everything looks fine. The <2.00:1 SWR bandwidth (BW) is about 1 MHz (27 MHz +- 500 kHz)
Then i put on the Reflector Element: The frequenz of lowest SWR decreases to 26.4 MHz. It try to fix this with the gamma match but no chance.
Okay i put on the 1. Director Element bt frequenz of minimum SWR decreases to 26.2 MHz (all SWRs are measured at 15 feed above ground).

Completely assemble your antenna. Make sure that you are at least 3.5 to 4 meters above the ground (minimum) before you start and that there is nothing close in proximity that would hinder your SWR readings. I personally only talk on 27.3850MHz so I made my beam resonant for that particular frequency. Once your antenna is completely assembled you can start to tune your antenna using your analyzer. If you find that your still more resonant below 27MHz (lower SWR readings) then you will have to adjust (shorten) your driven element some. (Do not cut it) Try to find the best balance for R=50 X=0 with your analyzer on your desired frequency. If your still having issues with SWR readings, you may have to raise the height of your antenna a bit and try again.

 

[CW61]

Hi

yesterday i made the setup and got an SWR 1:1.5 @ desired frequency.
In the evening I have built the antenna on a mountain of 900 m height.
I had many QSO the biggest distance was nearly 500 km (300 miles) via ground wave.
The Gizzy is really the best one i ever had on the mountain. I compare it to a Sirio Blizzard (very closed to a Maco 5/8): the Gizzy was 12 db better on ground wave.
I had made the G41 construction
55+73

 

[Unit 75]

Great news, CW61
Now enjoy your DX'inng

 

[Groundhog KSS-2012]

These old threads are interesting. My Dad had a

Gizmotchy beam back in the day. In the late 70's I believe. It had the vertical and horizontal side and If I remember right, was a 3 element beam. It worked great because he talked everywhere on it. Skipland wasn't a problem.​