Radioamateurs and Orbiter

[YL3GDY]

Hi All.

Just wondering is there any radioamateurs here in Orbiter-Forum? At this moment it looks like I am the only

For those whom it's interesting:

My call is YL3GDY (same with nick ), licensed since 2005.
Transceiver Yaesu FT-897, antenna Windom 40m long(for HF) + 3 element Yagi for 50MHz.
I am active on 7, 10 MHz in CW and (sometimes) in PSK31. When meteor showers are quite strong, also on 50MHz in JT6m.

 

[spcefrk]

KI4GKU

 

[Zatnikitelman]

KG4GUF-primarily on 2m on the Atlanta repeater, but I hope to expand into the HF General bands soon, just need to get that dang huge antenna

 

[Cobalt]

I've always thought it sounded interesting, but I've no clue where to begin getting into it.

 

[spcefrk]

I've always thought it sounded interesting, but I've no clue where to begin getting into it.

http://www.arrl.org

You can look up a local club. A lot of universities have school clubs, and every big city has a club as well as many small cities. They're almost always very friendly, keen on teaching, and looking for new members.

You just recently missed Field Day (like a yearly holiday of sorts) when a lot of clubs invite new people to try talking all over the world on amateur equipment. Getting your license is cheap and easy and most clubs will help you out with it.

 

[YL3GDY]

That's great that we have some hams up here.

By the way, would be ISS ever be workable on 50 MHz? Otherwise I will need to look for a new, more powerful rotator for a one more Yagi for 144 or 430 MHz.

73! de YL3GDY

 

[Danny Ramone]

Hi All.

Just wondering is there any radioamateurs here in Orbiter-Forum? At this moment it looks like I am the only

For those whom it's interesting:

My call is YL3GDY (same with nick ), licensed since 2005.
Transceiver Yaesu FT-897, antenna Windom 40m long(for HF) + 3 element Yagi for 50MHz.
I am active on 7, 10 MHz in CW and (sometimes) in PSK31. When meteor showers are quite strong, also on 50MHz in JT6m.

40 Meters is awfully long for 10 MHZ optimum for 10 MHZ is 21.75 M or 36.25 M but hey whatever works for you. I often find that usually the antennas you don't expect to work work the best.

I never got into HAM radio but I do military HF for a job, Hence my knowledge on antennas. We are constantly required to erect and take down antennae in a hurry.

If you have any HF questions I would always be happy to answer them.

 

[YL3GDY]

40 Meters is awfully long for 10 MHZ optimum for 10 MHZ is 21.75 M or 36.25 M but hey whatever works for you. I often find that usually the antennas you don't expect to work work the best.

I never got into HAM radio but I do military HF for a job, Hence my knowledge on antennas. We are constantly required to erect and take down antennae in a hurry.

If you have any HF questions I would always be happy to answer them.

Yes, I know that my antenna is a bit long for 10MHz band. Simply I work mainly on 7 MHz band (contesting, DXing). I look in 10 when a nice rare station working there. Anyway, I have quite powerful Z-match, which can adjust SWR almost to 1 on 7, 10, 14 MHz. Because of many trees around and low height of wire, the effect of possible exact length is very small.

By the way, which antenna types do you use? Simple lambda/2 verticals, or something more complex? Some radioamateurs use Ground Plane for 3,5 and 7MHz band (made from several fishing rods ) and find it very effective.

 

[Danny Ramone]

Its not that far out. As a rule of thumb for longwire/whip antennae. 72.85/frequency in MHZ will give you a 1/4 wavelength. The antenna can be any odd multiple of that number starting at 3 ( eg 3/4 wave lengths, 5/4(1&1/4) wavelengths etc. etc.)

But generally speaking it is difficult to create the perfect antenna mainly because its hard to get it the exact height off the ground it needs to be, plus trees etc can cause havoc. I like playing around with different configurations and seeing what I can get.
The best one I've had so far was a farmers fence!!!!

BTW SWR is only a match of the impedence from your co-ax to your antenna, it is not a replacement for resonance.

The antennas I use vary, we have field kits that will put up an inverted v or 1/4 wave dipole. We use those kits to make horizontal/vertical rhombics which have a nice NVIS effect (or we have a specialist NVIS antenna for that as well) But lately I have been into using field telephone wire (DON-10) to make our own antenna. Im a fan of the goold old longwire always seems to work whent hebooks tell you it shouldnt.

Ground planes can be very effective, especially where you want to give a virtual height above ground. Try using those fishing rods on one side only and see if it gives you more directivity.

 

[YL3GDY]

When I was planning my antenna, the main goal was to get a multiband. Hamradio bands can divide on two categories: main bands and WARC. Main bands are the oldest and their frequencies can be integrally divided - 3.5, 7, 14, 21, 28. They also are most popular. But WARC(10, 18, 24 MHz) were added much later, and they don't blend with main bands. I decided to count on main bands, that's because the length is 40m. But practically I have too high reactance even on 21 MHz.

When I was building my Yagi, I've used MMANA antenna modelling software to find approximate lengths of elements. But in real I've spend a whole day to tune it precisiously!