[snags]

Anyone have any knowledge/experience with one of the universal power antenna kits you can buy for about $80? Such as this one: http://www.ebay.com/itm/Power-ANTENN...83a039&vxp=mtr

[Carl S]

Are you planning to use one to replace an original unit in a 60's GM? If so, the new ones are wired different and if you want to use your stock switch you need to wire in 2 relays to use the stock switch. Easy to do, I did it and can help you through it if you like.

[Carl S]

Snags and I emailed back and forth and he got his antenna working on the stock switch using relays. If anyone else needs to do this, just holler. They're not all wired the same but regardless, there should be a way to make a new antenna work off an original switch.

[Carl S]

I had a request for this again, so thought maybe I should post my crude drawing in case anyone else is interested.

The bottom right corner shows the pin numbers for the relay.

[Engine-Ear]

Originally Posted by snags

Anyone have any knowledge/experience with one of the universal power antenna kits you can buy for about $80? Such as this one: http://www.ebay.com/itm/Power-ANTENN...83a039&vxp=mtr

This gives me a chance to distinguish the "power antenna" from an "AMPLIFIED antenna". Given that the original post's eBay link was a year old it takes you to listings for BOTH.

A "power antenna" is a radio antenna with an electrically motorized mast.

An "amplified antenna" is an antenna (either fixed-length or adjustable (and then either manual or motorized)) with a pre-amplifier in it (before it connects to the antenna jack on the back of the radio) with the intention of improving your signal reception.


As an aside...Some tech from me (for once!)

In terms of trouble-shooting, if it is radio reception you're trying to improve, perform a simple "A/B" test. Before you make any changes, get a pen and some paper, move the car out of the garage. Also buy one of these: http://www.napaonline.com/Catalog/Ca...017_0425567797. Unless you know the station frequencies in advance, grab the newspaper or get online and get a list of your local broadcast stations. Turn your radio on and tune to several stations on the AM (and the FM band, if equipped).

What's your reception like? Can you crank the radio volume up loud enough to be annoying? Make a note of reception 'quality', volume control 'scratchy-ness', objectionable background hum (both with the engine running and not), etc.

Now unplug your antenna cable from your radio. Plug the one in the link in to your radio - don't worry about either extending the mast or mounting the antenna to the body - let it lie on the carpeting or the seat. How does your radio reception experience differ?

...to be continued.

[Deadhead]

Now you need to give us a trimming lesson Uncle Matt.

[Engine-Ear]

Can and will-do.

More info coming soon, but remember: more metal in the air is generally better.

[Deadhead]

Originally Posted by Engine-Ear

Can and will-do.

More info coming soon, but remember: more metal in the air is generally better.

Got plenty of that!

[Engine-Ear]

OK, so if you have found that the reception performance improves considerably by deploying the antenna A/B test, your antenna co-ax cable and/or connector are bad.

If your performance does not improve, your radio and/or speaker likely needs internal, electrical restoration. ...And if you think about it, after 50+ years, that shouldn't be a surprise.

But I will tell you, after having my original speaker re-coned (to preserve the original 10-ohm impedance) and having the radio's RF (Radio Frequency) receive chain readjusted, replacing the electrolytic capacitors (whose internal electrolyte, a pasty dielectric material that stores charge but prevents 12V DC to pass thru), and disassembling and CORRECTLY cleaning the on/off/volume control (see pics), the radio sounds GREAT.

Parts and labor for the speaker re-cone was $75, and the radio was about $200. WORTH IT, especially when I added (insert shameless self-plug here) a RediRad to the car.

More to follow...

[Stuart]

It doesn't apply to our older cars, but if you have a 1970s big Pontiac with the antenna built into the windshield, chances are you have lousy radio reception. I used to have a '71 Catalina, and after a lot of messing around trying to improve things finally had to install a conventional aftermarket antenna on the fender.

[Engine-Ear]

The images below are all too common in original antenna feed wire (AKA Co-Axial (co-ax for short) cables). The crappy part is that most of us cannot properly replace the co-ax onto the fender bracket with out water egress or insufficient electrical connections.

In the image with the compromised outer jacket and shield (braided copper), this one also has a broken dielectric sleeve (the white, plastic boundary layer that resides between the shield and signal-carrying conductor in the middle). It made a nice funnel for rain water, and after years of holding water, the center conductor (which is electrically connected to the center 'pin' in the other image) actually deteriorated and carried almost no RF (Radio Frequency) signal at all.

This then leads to locating either a healthy, used original or finding an NOS antenna assembly. ...OR, fashioning up some sort of alternate antenna. There are two options here, both of them with plusses and minuses:

Option A: create an antenna from a length of antenna extension cable (such as this: http://www.amazon.com/Scosche-AXT18-...xtension+cable) by cutting off the female (socket) end and then carefully cutting off the braid (NOT the white dielectric sleeve) about an inch from the male (plug) end. You can hide this behind the dash and usually get local FM stations as well as stronger AM stations. Understand that this will never be as effective as a healthy antenna assembly that is mounted to the car body.

Option 2: Purchase a so-called 'hidden' (usually amplified) antenna. From the radiation-pattern measurement data I have studied and knowing a little about radio wave behavior, this option seldom leads to satisfying results.

[Pontiac62]

Originally Posted by Engine-Ear

OK, so if you have found that the reception performance improves considerably by deploying the antenna A/B test, your antenna co-ax cable and/or connector are bad.

If your performance does not improve, your radio and/or speaker likely needs internal, electrical restoration. ...And if you think about it, after 50+ years, that shouldn't be a surprise.

But I will tell you, after having my original speaker re-coned (to preserve the original 10-ohm impedance) and having the radio's RF (Radio Frequency) receive chain readjusted, replacing the electrolytic capacitors (whose internal electrolyte, a pasty dielectric material that stores charge but prevents 12V DC to pass thru), and disassembling and CORRECTLY cleaning the on/off/volume control (see pics), the radio sounds GREAT.

Parts and labor for the speaker re-cone was $75, and the radio was about $200. WORTH IT, especially when I added (insert shameless self-plug here) a RediRad to the car.

More to follow...

Is the $200 you mentioned for the radio, what we should expect to pay someone else, or did you perform the work yourself and spend $200 for parts???

Thanks, Les

[Engine-Ear]

Originally Posted by Pontiac62

Is the $200 you mentioned for the radio, what we should expect to pay someone else, or did you perform the work yourself and spend $200 for parts???

Thanks, Les

Les,

That is about what I paid someone else...in an attempt to 'vet' a handful of radio repairmen for the RediRad website, I sent some of my radios to a half-dozen shops that people had recommended. The median price paid was about $200 for P&L.

[Engine-Ear]

Originally Posted by Stuart

It doesn't apply to our older cars, but if you have a 1970s big Pontiac with the antenna built into the windshield, chances are you have lousy radio reception. I used to have a '71 Catalina, and after a lot of messing around trying to improve things finally had to install a conventional aftermarket antenna on the fender.

Thank you for mentioning that design, Stuart. I nearly forgot to comment on it.

If you think back to when your TV had an antenna on it, there were both 'rabbit ears' for VHF (channels 2 thru 13) and a loop (like this:http://www.radiomuseum.org/r/rembran...r_antenna.html) for UHF (channels 14 thru 83).

The loop (in particular) connected to the TV antenna terminals uses the flat, side-by-side cable (called a transmission line), which is 300-ohm 'twin-lead'. This impedance (like resistance for AC signals) matches well with loop antennas (details of which I will spare you at this time).

The rabbit ears are essentially a 'dipole' antenna. When the 'ears' are set at the best physical length for a given TV channel (a physics-based relationship exists between antenna size and the channel to be received), it matches well to a 75-ohm transmission line.

This is all foreshadowing for why (in my opinion) the windshield antenna was doomed from the start...

Going back to the example Stuart mentioned, visualize the wires embedded in the windshield, making a "T" between the glass layers. The vertical portion is the transmission line, and note that it is dimensionally similar to the 300-ohm twin-lead mentioned earlier. The two horizontal segments are the actual antenna elements.

Here are more culprits that conspired against the embedded dipole (in no particular order):

- Radio stations broadcast their signals using what is known as 'vertical polarization'. A receiving antenna mounted vertically will best-receive an incoming broadcast radio station signal. The dipole elements in our embedded antenna are horizontal, making even the best reception conditions a compromise vs. a similarly-sized vertical dipole. Strike one.

- In general, dipole antennas near other metal objects get 'detuned' from what they would otherwise be when in free-air on a plastic tripod. Being detuned means reduced efficiency. Another strike against this otherwise clever idea.

- A dipole that is the optimal length for a given signal matches well to 75 ohms (center of FM radio is 100 MHz, so its best-length dipole is about the width of a 69 Grand Prix windshield) - but the vertical part of the embedded antenna is about a 300-ohm transmission line... a 1:4 ratio. Inefficient but obviously unavoidable, given the physical circumstances in play. Strike three.

FWIW, antenna engineers earn their keep in industry by matching impedances for best signal transfer.

Still awake out there? Still interested in this topic? Got related questions?

[Carl S]

Just bumping this up so gto65lvr can find it. I guess he missed seeing the post with the wiring.

[gto65lvr]

thanks carl

[Carl S]

Let me know if you hit any obstacles.

[gto65lvr]

I wired it just like the diagram but it no works. the universal antennas have a constant to make it go down and the switched wire makes it go up and hold it up. with the relay set up I do no see how the monetary orig dash switch for the Bonneville will make this work correctly.

I cannot wrap my head around how to make the antenna go up and down manually with the factory switch and this new style antenna motor.

at one point it went up and then I got it to go down another time and have no clue why it worked that one time then not.

I know there has to be a way anyone can help me?

[brucee70]

Originally Posted by Engine-Ear

OK, so if you have found that the reception performance improves considerably by deploying the antenna A/B test, your antenna co-ax cable and/or connector are bad.

If your performance does not improve, your radio and/or speaker likely needs internal, electrical restoration. ...And if you think about it, after 50+ years, that shouldn't be a surprise.

But I will tell you, after having my original speaker re-coned (to preserve the original 10-ohm impedance) and having the radio's RF (Radio Frequency) receive chain readjusted, replacing the electrolytic capacitors (whose internal electrolyte, a pasty dielectric material that stores charge but prevents 12V DC to pass thru), and disassembling and CORRECTLY cleaning the on/off/volume control (see pics), the radio sounds GREAT.

Parts and labor for the speaker re-cone was $75, and the radio was about $200. WORTH IT, especially when I added (insert shameless self-plug here) a RediRad to the car.

More to follow...

Great Stuff Matt ...keep it coming! We all need more lessons like this ...

[Pontiac62]

Originally Posted by gto65lvr

I wired it just like the diagram but it no works. the universal antennas have a constant to make it go down and the switched wire makes it go up and hold it up. with the relay set up I do no see how the monetary orig dash switch for the Bonneville will make this work correctly.

I cannot wrap my head around how to make the antenna go up and down manually with the factory switch and this new style antenna motor.

at one point it went up and then I got it to go down another time and have no clue why it worked that one time then not.

I know there has to be a way anyone can help me?

Do you have the 3 position OEM momentary switch?
Did you get a wiring diagram with the antenna? If you could post that maybe I can help figure it out. Without a diagram we're kinda shooting in the dark
We need more information about the antenna and how the motor is wired.