1970's Hy Gain SP-500 VS. Avanti Astroplane

[ExitThirteen]

Got a question for the antenna guys here on the forums, has anyone done any kind of direct comparison of an original issue SP-500 and an Astroplane? My SP-500 has been beat up pretty bad over the last few years and I'm wanting to take it down and give it some TLC. I have a friend that has a NIB Avanti Astroplane he's willing to let go to me cheap.... would this be a suitable replacement for a SP-500? Or am I going to lose a bit of performance with the Astroplane?

I'm using galvanized water pipe for my mast currently, will this also affect performance of the Astroplane?

I do have a rather *cough*large*cough* amp I do run, but it's rare that it gets turned on, unless I'm trying to bust thru a pileup to get into my SSB club check-ins, how well do the Astroplanes handle the high output from the box?

Any info would be most helpful, would like to give my SP-500 the break it deserves!

Thanks in advance!


~Cheers~

 

[GnG8d]

How big an amp? That matters.

 

[ExitThirteen]

It does 650W PEP. Or, 1000W PEP for the Dosy meter lovers out there. LOL



~Cheers~

 

[Marconi]

Got a question for the antenna guys here on the forums, has anyone done any kind of direct comparison of an original issue SP-500 and an Astroplane? My SP-500 has been beat up pretty bad over the last few years and I'm wanting to take it down and give it some TLC. I have a friend that has a NIB Avanti Astroplane he's willing to let go to me cheap.... would this be a suitable replacement for a SP-500? Or am I going to lose a bit of performance with the Astroplane?

I'm using galvanized water pipe for my mast currently, will this also affect performance of the Astroplane?

I do have a rather *cough*large*cough* amp I do run, but it's rare that it gets turned on, unless I'm trying to bust thru a pileup to get into my SSB club check-ins, how well do the Astroplanes handle the high output from the box?

Any info would be most helpful, would like to give my SP-500 the break it deserves!

Thanks in advance!


~Cheers~

I've never had a SP500, but I have compared some of my vertical CB antennas. Here is a recap of the last series of signal reports I did in 2011.



There are good and bad issues with the Old TopOne version of the original AstroPlane. The Avanti may be a better made kit that is more durable compared to the poorly made Old TopOne, but between the Old Top One and the New Top One...I see a very small difference as noted above. During these 4 or 5 months of actual testing these two...I could hardly see any difference as I recorded the signals.

The big thing I noticed is how quite these two are compared to all of my bigger antennas when conditions are quite to reasonably quite. However, when conditions are noisy or there is a lot of static...all my antennas seem to be noisy.

Do you really have an original Avanti AstroPlane?

 

[ExitThirteen]

My friend has one, all original, new in the box, yes. And he's willing to let it go to me reasonable. I figured the Astroplane or a Sigma IV would be great choices to put up in place of my SP-500 while I take some time and give it the TLC it needs. Sadly, I don't have a way to get a Sigma IV, but I have an opportunity to get the Astroplane.



~Cheers~

 

[Marconi]

My friend has one, all original, new in the box, yes. And he's willing to let it go to me reasonable. I figured the Astroplane or a Sigma IV would be great choices to put up in place of my SP-500 while I take some time and give it the TLC it needs. Sadly, I don't have a way to get a Sigma IV, but I have an opportunity to get the Astroplane.

~Cheers~

You know you can still buy all the parts to the SP500 from HyGain. I know the SP500 will handle the power you want to use.

If it is tubing you need, make sure you discuss the taper fit with HyGain. They used tapered tubing back in those days and maybe they still do, but who knows if the swagged fit today will still work with your old tubing.

I recall that these parts in the bottom area are reported to be a little different from your old parts also, including the 2 matching wires, hub, and the upper support for the wire matcher.

If you need the matcher, consider that there may have been changes in the way this wire device is attached to the hub and the radial. You may need the other new parts that go with this area also because of the changes.

If for any reason you decide against taking the AstroPlane, get a price from your buddy, and I'll buy it...if the price is right. I never owned one of the originals.

 

[hotrod]

i havent done any tests like that. but from reviews from this forum the astroplane
might have quieter recieve . and could perform just aswell as the p500 if the tips
are same height. homer bb and marconi are the guys to ask on this. but if price
is cheap i say try it. if ya dont like it sell it for what ya got into it on here.mho

 

[HomerBB]

I do not have a SP500, either. I have compared the original AP to other 5/8 GP antennas. As said, if the top of the antennas are flown at the same height the AP will keep up with the 5/8 GP. If the bottoms are the same, the AP will have nearly the same performance to the point that it may not be noticed for any difference between the antennas.
As for power, I have put up to 400 watts into the AP with no problems. Based on the way it is made mechanically, I believe it could handle your wattage, but have no experience with as much into the Astroplane.
I agree that the antenna is worth a trial. Another person giving us a report on the AP performance would be nice. I have grown so fond of it that I may be too partial to be objective any longer. Also, antennas tend to respond differently at different locations, so if you decide to get it into the air I'd be intersted in hearing what you think of it.

 

[KC9Q]

Page 5 of the ASTRO Plane manual I have says it will handle 2 KW.

 

[Marconi]

Page 5 of the ASTRO Plane manual I have says it will handle 2 KW.

I might agree KC9Q, both the A/P, and Top One might easily handle 2000 watts if the antenna is good and tight all around and fully secure. I have only used the Top One version however, but over time I found that the antenna can fail to maintain good continuity.

The first time I saw this...the top plug that is compression fitted in the tubing, and holding the top hat wires had come loose. This plug was spinning around in the top of the radiator tube. I checked it, and it showed continuity, but when I twisted the plug...the continuity was no longer steady.

The next time I saw this it was the same problem in the bottom plug that screws into the mount is compression fitted also. On the Top One all the elements have studs at one or both ends. They screws into the antenna. These plugs are secured by compression fit into the aluminum tubing. I figure with wind blowing...these plug fittings can work loose. I fixed them by drilling a small hole and putting a screw in each plug.

The original AstroPlane uses a two piece mounting hub to secure the tubing by compression fit of tube inside of tube. IMO, this is much better construction.

IMO, if you ever see your SWR fluctuate wildly or you start to see TVI sudenly...then the antenna is likely loose somewhere. In my experience my Top One created all kinds of TVI type interference and the SWR was variable too.

I do not have a SP500, either. I have compared the original AP to other 5/8 GP antennas. As said, if the top of the antennas are flown at the same height the AP will keep up with the 5/8 GP. If the bottoms are the same, the AP will have nearly the same performance to the point that it may not be noticed for any difference between the antennas.
As for power, I have put up to 400 watts into the AP with no problems. Based on the way it is made mechanically, I believe it could handle your wattage, but have no experience with as much into the Astroplane.

I agree that the antenna is worth a trial. Another person giving us a report on the AP performance would be nice. I have grown so fond of it that I may be too partial to be objective any longer. Also, antennas tend to respond differently at different locations, so if you decide to get it into the air I'd be intersted in hearing what you think of it.

I agree with Homer and I would be interested to see your results also.

 

[Tripple Nickel]

Never did own one, but I can tell you there were a lot of them back in the day. Most everybody had some type of juice then and not the small transistor type. Never heard one that sounded bad, JMHO, good luck and Buy it, as mentioned someone will buy it from you. Good day,
555

 

[MarkIV]

I tried the reincarnation of the AP. What a piece of junk! TVI back then.
Folded 5/8 yeah right. There is no such thing! Much better choices out there.

 

[HomerBB]

Howdy, Mark.
Should have bought a better TV.
I never had any problems with my Astroplanes.
Just get them in the air, and properly use a Common Mode Choke. Never bothered any electronics and made lots of contacts local and DX.

 

[Arch Stanton]

I had an original Astro Plane back in the 70’s it was the first antenna that I had.
For a 12 year old rookie it was great. 1.2 to 1 match around the band but slightly higher on 26.965.
The only problem that I can remember was an odd noise during some heavy rains, not all rain just some.
I used that antenna many years before putting up a PDL II. I ran a 12 tube Phantom into it a lot with no problems but that’s not a huge amount of wattage by today’s standards.