More InnovAntennas Fun

Well,

You may remember my sharing an instruction sheet from an InovAntennas purchase back here and basically explaining how poor I though the instructions were. Well, here's another excellent example:

So, credit where credit is due - this time I didn't actually have any missing parts for the antenna itself; however I did have some spare bits for the antenna (some extra end caps and element clamps) and unfortunately the antenna to boom mounting plate and associated u-bolts are missing completely.

But lets take a look at the instructions:

1. The title tells me it's a 1.4m antenna; I assume that's the boom length, but, oh no, the boom is 1.7m long.
2. The bottom of the page tells me the boom is 1.7m long - so which is it? Let's get a tape measure and check.
3. The bottom of the page also also tells me that "guy and supports are supplied" - I don't think so.
4. So let's look at the shortest element - there are three numbers 1705mm, 1405mm and 903mm. So I think one of these (the 1705) is the distance from the boom end, the 903 is the element dimension - no idea what the 1405mm is - perhaps this is for the 1.4m antenna mentioned in the title that I haven't got? If that 1703 is the distance from the boom end then the first element is nearly a foot from the boom start - that can't be right either.
5. Then we have the added information "X-POL SIZES"; you have to assume this is for a cross polarized variant perhaps?

But once again, no actual information on which bolts or other bits to use where. One of the driven element clamps is metal - now I assume that's not at the end the feedpoint is and it seems the feed is at the back. I assume I need a coax balun near the feedpoint but that's clearly guesswork as there is no information on that aspect at all.

Local conditions.

6&4M Antenna and other Musings

Well,

I decided a while ago to remove the large 6/4M combined antenna I have - it's very big and heavy:

So, I decided a while ago to replace the 6/4M antenna with a 3 + 3 ele version that we originally bought for the UK ACs; this antenna had very little front to back so I wasn't happy with it for home. I've now decided to purchase the 4 + 4 ele version. All these antennas are from Innovantennas.

Now, I've bought quite a few antennas from them in my time - perhaps 10 or more. Every single one has had either no manual (sent by email normally), missing parts, the wrong parts or even one had the boom drilled incorrectly. This 4 + 4 ele is a bit better, it only had one broken pipe clamp. The instructions you receive from InnovAntennas are poor at best, but this example has to be the worst yet; take a look:

Now, there's something scribbled in the top right that looks like "ADD over Cap" - no idea what that means.

There's a box drawn on the 4M driven element and then scribbled out.

There's a box drawn on the 6M driven element with a scrawl that says "Plate oh tend Point" (I think this is plate at feed point) so we conclude that this was first scrawled on the 4M driven element and then crossed out.

Nothing to tell me which bolts to use where or anything resembling how to put it together.

Great antennas - rubbish quality control and instructions!

I've also continued the theme of 'scope obsession by making a circuit from W2AEW. This is a means of converting a composite video output (from say a camera) and displaying it on a 'scope screen by using the X, Y and Z inputs:

My build looks like this:

and it works a treat!

When Miss Luna Cat rolls on her back like this in front of Elmo Dog, this is interpreted, in human speak, as "thank God it's spring".

Local conditions.

Antenna Complete!

Well,

Perhaps you remember the antenna I started to put together last weekend and then realised that the bits for the 6M sections were the wrong size? It was back here:

http://g0mgx.blogspot.co.uk/2013/05/thatll-never-work-will-it.html

The correct parts arrived today to complete the antenna, so the tower has been down again. I've just flicked through the archive from "Antenna Cam" and here's me up the ladder fiddling with the top bracket prior to dropping the tower down:

If you look closely in the above image you can see me fiddling, but you can also see that the closest element on the HF beam is a bit "out of bonk". Here's the antennas back up again and I've fitted the parts to the 4/6M beam and also straightened out the HF element:

And finally here's an image of the antennas back up with the weather a little clearer and them pointing back to the SE:

The 6M part of the top beam is no longer resonant at 55MHz, but seems to be a good match on the 50MHz amateur band!

It's perhaps just a little too short but it's more than acceptable for my requirements; the resonant point on 4M or 70MHz hasn't moved.

Good, egh?

That'll Never Work - Will it?

Well,

The VHF antennas here have always been somewhat of a compromise. Recently I moved my 4M or 70MHz antenna from the side of the house and put it on top of the HF antenna on the main mast. I also took down and filed (in the hedge) a 6M or 50MHz antenna. I saw this a while ago and wondered... could this really work:

InnovAntennas 4 & 4 ele

So, you guessed it, I bought one.

Here's the antenna as it starts to go together:

As you can see, there are 4 elements for 6M and 4 elements for 4M on the same boom. The thing that I didn't (and still don't) understand is how the thing works electrically as the 4M elements are all parasitic (there's no wires connected to them from the RF supply). The antenna has a direct coax connection without any kind of connector:

There's plenty of self amalgamating tape under the white PVC tape you can see, the connections themselves were then coated with Copper grease. The antenna also needs a coax wound balun - this is preventing me from feeding the antenna directly with Westflex 103 - it's just too thick to wind tight enough. I've had to connect a length of RG213 to the antenna, use that for the balun then have a join to the 103 close to the boom.

I then brought the tower down and changed the antenna on the top for this one:

While the antenna was in this position I attached the analyser thingamabob; the 70MHz resonance looked really good, but the 50MHz resonant point was more like 55MHz.... hmm I thought, perhaps I should raise the antenna and see.... no change at all.

I scratched my head for a while and re-checked all the dimensions - they seemed correct to me, here's the diagram I was following:

Suddenly I realised that the element centres that are labeled as 1800mm on the diagram are only 1500mm on the antenna! A quick email to InnovAntennas confirmed that I had indeed got the wrong parts.

The antennas are back in the air:

But the 6M or 50MHz elements on the top antenna are currently exactly 300mm too short.

Useless, hugh?