C3 Radio Reception

[Robert S.]

I read with much interest the recent post on Wonderbar radio reception problems. I have much the same issue on my 74' with a checked/ repaired OEM radio with new speakers and new antenna lead. FM reception is fine but AM reception is very, very poor and improves if I touch the antenna mast. T******* the radio provided no help. I removed the ground plane, un-rivited it and cleaned up the aluminum corrosion and oxidation on the steel center plate and reassembled making sure the ground contact with the frame was good and this provided no help. I changed the antenna mast out with an OEM mast (mine is a reproduction mast) from a 75'-again no help. At this point I am assuming it must be an issue with the new antenna lead which was purchased from Paragon about 2 years ago.
Questions:

1.) anyone else have this problem on a C3 and how was it solved?
2.) What vendor should I use to purchase another antenna lead that has a good chance of working?

[Ralph S.]

Re: C3 Radio Reception

I had the same problem on my 73 and i pulled the antenna wire out of the radio slightly and it worked perfectly on AM.

[Joe L.]

Re: C3 Radio Reception

I read with much interest the recent post on Wonderbar radio reception problems. I have much the same issue on my 74' with a checked/ repaired OEM radio with new speakers and new antenna lead. FM reception is fine but AM reception is very, very poor and improves if I touch the antenna mast. T******* the radio provided no help. I removed the ground plane, un-rivited it and cleaned up the aluminum corrosion and oxidation on the steel center plate and reassembled making sure the ground contact with the frame was good and this provided no help. I changed the antenna mast out with an OEM mast (mine is a reproduction mast) from a 75'-again no help. At this point I am assuming it must be an issue with the new antenna lead which was purchased from Paragon about 2 years ago.
Questions:

1.) anyone else have this problem on a C3 and how was it solved?
2.) What vendor should I use to purchase another antenna lead that has a good chance of working?

Robert------


There is an antenna trimmer adjustment on the radio. It is just below one of the knobs (I forget which one) and can be accessed by removing the knobs. It can be adjusted with a small, slotted screw driver. I would suggest trying this adjustment to see if you can improve AM reception.

[Robert S.]

Re: C3 Radio Reception

The T***** in my original post was meant to say that t******* the radio provided no help.

[John H.]

Re: C3 Radio Reception

The T***** in my original post was meant to say that t******* the radio provided no help.

Robert -

The censor robot doesn't like the word "r i m m i n g", so it replaces that string with asterisks; if you want the word "t r i m m i n g" to show up, you have to put spaces between the characters to "fool" the robot.

[Rich C.]

Re: C3 Radio Reception

Wow, "t r i m m i n g' is a naughty word? Everybody pays because some idiot may use obscene language, whats next word police? Back to the main point though; my FM on my '73 is so-so, the AM is non-existent, live in a mountainous area though.


'73 LS-4 454, owned 22 years!

[Joe L.]

Re: C3 Radio Reception

Wow, "t r i m m i n g' is a naughty word? Everybody pays because some idiot may use obscene language, whats next word police? Back to the main point though; my FM on my '73 is so-so, the AM is non-existent, live in a mountainous area though.


'73 LS-4 454, owned 22 years!

Rich-------

It sounds to me like your radio might benefit from a "going-through" by a qualified radio repairman. However, keep this in mind: this radio employs technology that is over 40 years old. Most of us are now used to radio technology that's, at most, only a few years old. There's a big difference.

[George J.]

Re: C3 Radio Reception

Robert,
I, too had my radio refurbished and installed a new antenna lead, but the reception is still not perfect, with AM almost non-existant. I, also, bought the lead from Paragon, and I am thinking that it may be bad, or I damaged it somehow during installation. I am next going to try and connect another antenna, just to verify it is the lead.
Please let me know how yours turns out.

George

[Wayne P.]

Re: C3 Radio Reception

Just a thought would you have another newer radio just to try ? I had a new radio worked grate. replaced it when I had mine repaired and have a lot of static. I assume the new radios have a something inside to dampen the engine noise. Now I just listen to the off road mufflers.

[Robert S.]

Re: C3 Radio Reception

I really believe the root cause of the issue I am having with poor C3 AM reception must lie with the antenna cable. I mentioned in my original post the TDB discussion about a week ago regarding older Corvette radios (Wonderbar types). Jerry Rudbeck mentioned that Wonderbar radios needed antenna cables using 93 ohm wire (not the 75 ohm stuff that is readily available today for TV use) and that the OEM leads had a capacitor built into them. His reply indicated that some of the replacement cables being made today did not use 93 ohm wire and did not have the capacitor feature built in and the lack of these features resulted in poor AM reception while FM reception remained good.
So it made me wonder if these same comments apply to C3 Corvette radios? In particular, if the comments do apply, then who today is making antenna leads for a C3 that have the electrical features necessary for proper AM reception?

[Rich C.]

Re: C3 Radio Reception

There are still old stock ones out there. I found one a couple of years ago, in the AC bag no less! The outer jacket has a subtle 'alligator skin' look to it. I could probably check the resistance of it, if that would be of any help

'73 LS-4 454, owned 22 years

Collecting NOS parts for the eventual restoration for 21 of them!