FM Radio Antenna Considerations

[Tom Sawyer]

With a 1/4 wave vertical antenna, you want the shield of the coax at the antenna end connected to the ground and not floating. That forms the ground plane. If you attached the antenna to the steel chassis, sure that would work, but not sure how you arrange the antenna itself. RF does not use the same rules as DC signals.

Are we talking reception or transmission here? For transmitting I can see your point.

 

[Yukon Cornelius]

Rules are the same for Rx and Tx.

 

[Tom Sawyer]

Portable AM/FM radios with plastic cases work ok without a ground plane...

Eh, I may never know since I doubt I'd install a radio. We'll know more closer to production!

 

[Yukon Cornelius]

True. They don't have a coax cable connected between the radio circuits and the antenna either. The antenna will work, it just won't work to it's full potential. a piece of wire jammed in the radio antenna connector will also work, just not as well as other options.

 

[Luxrage]

With a 1/4 wave vertical antenna, you want the shield of the coax at the antenna end connected to the ground and not floating. That forms the ground plane. If you attached the antenna to the steel chassis, sure that would work, but not sure how you arrange the antenna itself. RF does not use the same rules as DC signals.

That's my plan, I'm hoping to install a traditional whip style or take one of the motorized antennas from my parts bins and integrate one on the front right fender. I'm hoping that whatever mounting point the composite panels have to the metal unibody frame underneath will be a sufficient ground for it. Depending on the layout of the sheet metal underneath it may not be too much more to create an L bracket that mounts inside the fender-panel for it.

I think trial-and-erroring the initial projects for the Slate for the early adopters is half the fun.

 

[bartflossom]

One of these would fulfill my 70s/80s vibe, but since the hood goes over the fender, not sure how it would be mounted.

 

[SparkYellow]

I get it now. This is not about special stations to listen to. This is about period-approciate tech or old-tech like in Mortal Engines. AM/FM radio fits nicely in a barebone truck with crank windows.

 

[SparkYellow]

Do you mean KOST or WRBO? I'm not sure why you would have to install a radio for either when you have your phone.

https://www.kcsm.org/blog

With the two links at the bottom, one can launch the player to stream from any browser. I am going to try them again, to see/hear if they're still asking for support. 😅

 

[KJRaven]

I am planning on installing a fm radio in the slate. A task that I have done before. However slate won't already have an antenna.
Could some of the folks who have experience with radios and electronics comment for the rest of us. what things do we need to consider to get good reception?

I think i would start here. there are a few options, one is completely hidden, another mounts to the glass, another can mount to the roof. None of them are expensive and should work okay enough to listen to the radio, but may need to be adjusted to get the best signal.
Might be trial and error until we get the trucks and do some testing to find the best fit.
Hopefully Slate does some work and finds us a good option to go with a radio install kit. https://www.crutchfield.com/g_513550/Universal-fit-Antennas-Adapters.html?tp=101684

 

[KevinRS]

I think i would start here. there are a few options, one is completely hidden, another mounts to the glass, another can mount to the roof. None of them are expensive and should work okay enough to listen to the radio, but may need to be adjusted to get the best signal.
Might be trial and error until we get the trucks and do some testing to find the best fit.
Hopefully Slate does some work and finds us a good option to go with a radio install kit. https://www.crutchfield.com/g_513550/Universal-fit-Antennas-Adapters.html?tp=101684

My thinking, if I were to decide to add a radio, is that the glass mount type, don't need to be mounted to the glass, when you have non-metallic body panels. You should be able to mount them to one of those body panels, and have a completely hidden installation.

 

[Luxrage]

One of these would fulfill my 70s/80s vibe, but since the hood goes over the fender, not sure how it would be mounted.

Agh, you bring up a good point. Looking at the 160k teardown video there's definitely no space to even stick the slimmest antennas on the fender without it being in the wheel arch:

At least there appears to be sufficient metal framing under the hood for something like this. Not very integrated but gets the job done. Either that or the rear corner / bumper mounts:

Edit: OK, hear me out...

 

[Tom Sawyer]

Edit: OK, hear me out...

That looks like a CB antenna, right? It appears the conversation has moved from discussing an antenna for FM broadcast reception.

Not sure I'd want to sit so close to a transmitting antenna so close to my head. I suppose it depends on radiated power. For this use case, a ground plane would certainly benefit performance. Something like this (click on the picture - I made it a link to the product on Amazon):

 

[Luxrage]

That looks like a CB antenna, right? It appears the conversation has moved from discussing an antenna for FM broadcast reception.

I wouldn't be using it for CB, but it is somewhere that a power FM antenna motor could go underneath. A power antenna would be more rigid than a whip and wouldn't smack against the cab. That upper pickup bed trim ~should~ be removable for the SUV top / interior so maybe it wouldn't be so hard to access... Putting it in the back bed corner would be fun as well...

 

[IamSpotted]

But it's not a safety issue.

You will find the majority in that thread dont see it as a safety issue either. I'm not interested in an FM radio as far as getting radio stations is concerned. But I do want to add a CB at the least. My main concern is getting a good ground plane with the panels being composite. There is a metal from but that doesn't compare to a nice large roof panel, or a hood, etc. That shouldn't be an issue for an fm radio though