Buying An Astroplane

[homerbb]

Unless things change between now and Monday I will be picking up an Astroplane that looks like the photo except the lower mounting bracket is missing. That shouldn't be difficult to fit. I'm paying $25. Fair price?

[Sandbagger]

Dec 3, 2010 19:59:01 GMT -5 homerbb said:

Unless things change between now and Monday I will be picking up an Astroplane that looks like the photo except the lower mounting bracket is missing. That shouldn't be difficult to fit. I'm paying $25. Fair price?

It is if it's in good condition. Any time you buy an antenna that's been up in the air for a few years, the hardware tends to rust, and that can make things tough.

OTOH, if it's NIB, it's an excellent price, even if the fiberglass rod and clamps are missing.

[homerbb]

It is in the air. (It's a bit out of character for me to buy a base antenna, but I'm making an exception for this one). It needs cleaning up, replacing the hardware with SS, and try to put the missing bracket back in. It may be a little misshapen near the top, but I won't be sure until I get it off the mast it is on and in my hands. I'll pay particular attention to the feed point.
Can hardly wait to look it over up close and personal. I've been talking to him on and off for nearly a year. He finally said yes.

[dgtr43]

Is it the Avanti Astroplane (the original) or the Top One (clone) made by Sirio? Which one are you buying? You might want to check.

[homerbb]

I am convinced it is the Avanti Astroplane.

[hotrod]

Dec 4, 2010 17:59:25 GMT -5 dgtr43 said:

Is it the Avanti Astroplane (the original) or the Top One (clone) made by Sirio? Which one are you buying? You might want to check.

why is that?i was looking at the sirio top one. seems like it
should work similiar and be toploaded. i was thinking of this antenna for myself cause i got height limits. thought see may help me get out better.i got a 2016 at 10feet now

[hotrod]

Dec 5, 2010 11:48:15 GMT -5 hotrod said:

Dec 4, 2010 17:59:25 GMT -5 dgtr43 said:

Is it the Avanti Astroplane (the original) or the Top One (clone) made by Sirio? Which one are you buying? You might want to check.

why is that?i was looking at the sirio top one. seems like it
should work similiar and be toploaded. i was thinking of this antenna for myself cause i got height limits. thought see may help me get out better.i got a 2016 at 10feet now

oh if it helps i live down in a valley too. makes it all worse

[homerbb]

I could be wrong, but I think his point is that the new top one is so well priced that any money out on a used one would not make sense. However, getting an original Astroplane for the sake of having and restoring the old-timer should be worth it.

[Sandbagger]

Dec 5, 2010 11:49:35 GMT -5 hotrod said:

Dec 5, 2010 11:48:15 GMT -5 hotrod said:

why is that?i was looking at the sirio top one. seems like it
should work similiar and be toploaded. i was thinking of this antenna for myself cause i got height limits. thought see may help me get out better.i got a 2016 at 10feet now

oh if it helps i live down in a valley too. makes it all worse

Well, based on my own experiences with the Astro Plane back in the 70's, if you are looking to climb your signal out of a valley, the AP is not the antenna to do it. Back then, I used to live in a valley, and I tried a 1/2 wave Radio shack antenna, an Astro Plane, a 5/8th wave Hustler Trumpet, and an Avanti Sigma IV. The order that I listed them is also the order of least to best in signal strength. Each antenna was mounted on 20' of mast on the side of my house at 175' ASL (HAAT was 219'). I've known other guys in better locations who were able to mount their AP's higher up, and they worked fairly well. But not for me. As usual, YMMV........

[homerbb]

Sandbagger, what are your thoughts on a 1/4 wave ground plane for helping with a down in a hole situation?

[Sandbagger]

Dec 5, 2010 18:22:32 GMT -5 homerbb said:

Sandbagger, what are your thoughts on a 1/4 wave ground plane for helping with a down in a hole situation?

A 1/4 wave GP has no gain, so right away you're at a disadvantage. Getting out of the hole requires an antenna with a slightly higher angle of radiation, which I've read, the Sigma 4 has. That's likely the reason why that antenna did so well for me, while other have said a .64 wave GP will out do it in more favorable height situations where the lowest radiation angle is desired.

[homerbb]

Maybe these fellows can profit from the use of a .64 or a sigma 4.
I haven't got such a problem where I'm at.

[cbrown]

I agree with Sanbagger. If you are 'down in the hole' you want an antenna with as much gain as you can get.

[homerbb]

Ditto. I just wanted those needing the info to get it from those who know the most.

[hotrod]

well thank you very much guys. i can talk north-east real good considering my location
but tring to get south/southwest thats another whole story. i asked cause obviously
the astroplane would be easier to get up higher than say the sigma4.however the sigma definately has more gain.but being a 27 plus foot antenna a 20foot pipe would probaly
be about all id be able to have under it.

[homerbb]

Here it is, at last:

[homerbb]

Dec 4, 2010 17:59:25 GMT -5 dgtr43 said:

Is it the Avanti Astroplane (the original) or the Top One (clone) made by Sirio? Which one are you buying? You might want to check.

Perhaps the photos help me to determine whether it is an original or not . . .

[Sandbagger]

Dec 7, 2010 15:45:37 GMT -5 homerbb said:

Dec 4, 2010 17:59:25 GMT -5 dgtr43 said:

Is it the Avanti Astroplane (the original) or the Top One (clone) made by Sirio? Which one are you buying? You might want to check.

Perhaps the photos help me to determine whether it is an original or not . . .

I'm not sure now close Sirio copied the original Avanti design, but those pictures sure look like the original.

[homerbb]

I still think it is an original. The age it appears to be would likely have resulted in more deterioration from a poorly constructed knock-off I'd think. So, while I understand there were some copy-cat knockoffs here and there, the latest of the Sirio top one antennas I've seen look like this:



Unless I find a good reason to think otherwise, I will assume the one I brought home is the Avanti model.

[cbrown]

It sure looks like the Astroplane.

[homerbb]

Dec 8, 2010 10:51:21 GMT -5 cbrown said:

It sure looks like the Astroplane.

yup

[zman]

I have one laying in the weeds behind the garage.

[homerbb]

Dec 23, 2010 20:18:25 GMT -5 zman said:

I have one laying in the weeds behind the garage.

What!
Is that any way to treat the old thing?
Still in decent shape?

[homerbb]

Got the Astroplane in the air. The bottom of the loop is @ 38' The coax feed point is @ 45.5' and the top of the antenna is about 49'.

SWR: ---------- @50w DK ------- @5w DK
28.855 -------------- 3+ ------------ 1.9:1
28.305 ----------- 3.0:1 ----------- 1.5:1
27.855 ----------- 1.9:1 ----------- 1.2:1
27.555 ----------- 1.7:1 ----------- 1.1:1
27.405 ----------- 1.6:1 ----------- 1.1:1
27.205 ----------- 1.3:1 ----------- 1.1:1
26.965 ----------- 1.1:1 ----------- 1.0:1
26.515 ----------- 1.3:1 ---------- <1.1:1
26.065 ----------- 2.9:1 ----------- 1.5:1
25.615 -------------- 3+ ----------- 2.3:1
25.165 -------------- 3+ ----------- 2.0:1

[Sandbagger]

Jan 3, 2011 13:59:20 GMT -5 homerbb said:

Got the Astroplane in the air. The bottom of the loop is @ 38' The coax feed point is @ 45.5' and the top of the antenna is about 49'.

SWR: ---------- @50w DK ------- @5w DK
28.855 -------------- 3+ ------------ 1.9:1
28.305 ----------- 3.0:1 ----------- 1.5:1
27.855 ----------- 1.9:1 ----------- 1.2:1
27.555 ----------- 1.7:1 ----------- 1.1:1
27.405 ----------- 1.6:1 ----------- 1.1:1
27.205 ----------- 1.3:1 ----------- 1.1:1
26.965 ----------- 1.1:1 ----------- 1.0:1
26.515 ----------- 1.3:1 ---------- <1.1:1
26.065 ----------- 2.9:1 ----------- 1.5:1
25.615 -------------- 3+ ----------- 2.3:1
25.165 -------------- 3+ ----------- 2.0:1

There really should be no difference in SWR in an antenna from 5 watts and 50 watts. The higher readings at 50 watts indicates either a mismatch at the amplifier end, spurious content in the amp, or a difference in the SWR meter's linearity at different power levels.

[homerbb]

I agree with you. I posted the differences to see what others might suggest. On the 5/8 wave, and a dipole, I get a difference in reading of only about a .2:1 reading, as in a reading of 1.0:1 reads 1.2:1. This antenna is made for CB so it doesn't surprise me that the SWR curve is dramatically higher off band, but I wondered what was up. I think it may be the amplifier. It is a Palomar 250 base amp.

That said, With skip running like it is I can't say what local performance is like, but it seems to do just fine with DX.

186 -------------------------- NY Winchester Radio
125 -------------------------- NY
Black Magic ----------------- Quebec, Canada
RC427 ----------------------- Niagara Falls, Canada
373 -------------------------- Canada
606 -------------------------- Canada
265 -------------------------- Ontario, Canada
577 -------------------------- Ottawa, Canada
8620 ------------------------- Toronto, Canada
579, Dr Smooth ------------ Ontario, Canada
427, Mark ------------------ Lake Erie
489, Frank ----------------- Lake Erie, Canada
355 -------------------------- Ontario, Canada
130 -------------------------- PA
751 -------------------------- Canada
323 --------------------------
392 -------------------------- PA
441 -------------------------- Lake Erie
#29 -------------------------- PA
136 -------------------------- PA mobile
290 -------------------------- PA
8017 ------------------------- Central OH
105, Kenny ------------------ NJ
357 ---------------------------
123 --------------------------- Cleveland, OH
210 ---------------------------
579 ---------------------------
462, Cowboy ----------------- OH
138 ---------------------------- Columbus, OH
Hotrod ------------------------ KY
357 ---------------------------- KY
Bright Eyes ------------------- Hartford, KY
Gate Keeper ------------------- MD
33 ------------------------------ KY
Moonshiner ------------------- KY
Waterboy --------------------- KY
205, Hotrod ------------------ VA
499 ---------------------------- VA
420 ---------------------------- KY
252 ---------------------------- KY
214 ----------------------------

[cbrown]

Jan 3, 2011 16:57:19 GMT -5 Sandbagger said:

There really should be no difference in SWR in an antenna from 5 watts and 50 watts. The higher readings at 50 watts indicates either a mismatch at the amplifier end, spurious content in the amp, or a difference in the SWR meter's linearity at different power levels.

I agree, the SWR is a ratio and should stay the same no matter what the power level.

Homer, are you recalibrating the meter when you bump up the power level?

[homerbb]

Yes, sir,
I'm recalibrating every time I change the power, and the location on the bands. I think it is mostly a matter of a less than clean Amp. I am running the SWR meter between the amp and the antenna.

[Sandbagger]

Jan 4, 2011 17:28:22 GMT -5 homerbb said:

Yes, sir,
I'm recalibrating every time I change the power, and the location on the bands. I think it is mostly a matter of a less than clean Amp. I am running the SWR meter between the amp and the antenna.

Try sticking a low-pass filter on the output of the amp and repeat the test. Chances are that the SWR readings will fall closer together.

[homerbb]

I guess I'll have to pick one up. Thanks for the tip.