Michigan Radio & TV Buzzboard

DJ-MichaelAngelo wrote: ↑

Thu Nov 23, 2023 9:06 am

bmw wrote: ↑

Wed Nov 22, 2023 9:44 am

$14 new-old-stock Vintage pair of 39-inch rabbit ears:

https://www.ebay.com/itm/126163551108

thanks BMW - I might just go this route!

Geez I've thrown out a few of those. Never thought to eBay them. I probably still have a couple in a box I could make a few bucks off of!
A couple of chunks of good old 300 ohm twin-lead and you've got yourself the makings of a folded dipole that you can hang from anywhere or throw behind the furniture.

bmw wrote: ↑

Wed Nov 22, 2023 9:44 am

Are there any stores still left in the Grand Rapids area that sell these 75/300 ohm adapters, where I can buy them in person? I miss Radio Shack! lol -- I know I can order them super cheap online, but it'd be nice to have a local source where I can purchase and have them immediately, not wait days for shipping. I did try Best Buy but no luck there.

audiophile wrote: ↑

Thu Nov 23, 2023 7:26 am

Get a real antenna

https://www.newark.com/stellar-labs/30- ... dp/97W3565

I have one of those antennas and it is pretty good.

I also did this mod and it helps a bit. http://ham-radio.com/k6sti/stellar.htm

Try using power cord or yard light wire, and you can buy it by the foot at Home Depot off the roll, and separate the two sides by pulling them apart to about 5 feet (separate about 30 inches of it). It figures out to be in between 75 and 300 ohms characteristic impedance, and it's better than speaker wire. It seems to match either 300 or 75 ohm inputs fairly well. But I also agree, at least get the Stellar Labs 4 element Yagi for the lower power Grand Rapids stations, like the 88-92 MHz NCE FM stations, if possible.

I had a piece of two conductor cord that came from a Malibu Light Timer/Transformer that I wasn't using. I wanted to estimate the Impedance of the Balanced Line and found this formula for balanced line.

Here are the impedance computations.

Zo = (276/sqrt(ε))* log(2*S/d)

I measured and estimated the cord, 3/16" between conductors, 1/16" diameter conductors, 2.2 dielectric constant for the poly plastic insulation.

So 276/SQRT 2.2 X LOG 10(6)~=145 Ohms

Pulled the wires apart to ~32 inches each side. Taped to window frame. Hooked up to 300 ohm input. Haven't compared it to hooking it up to the 75 unbalanced input to see if it's a better match.

If you have a cable box or DVR with microprocessor plugged into the same circuit as your home theater receiver, try unplugging that device.

I know for a fact some of Comcast's equipment creates interference on certain FM band frequencies.

Their 4K-capable X1 DVR at my house created terrible interference from about 92.1 MHz to 93.3 MHz. A 50 kW equivalent FM station four miles down the road from me was sometimes difficult to pick up cleanly. As soon as I cancelled my cable TV and returned the cable box, the reception issues at 92.3 FM, 92.7 FM and 93.1 FM completely went away.

My theory is a signal of some kind is transmitted just below 72 MHz (the old analog channel 4) through the cable lines, and this creates a shadow image ~21.4 MHz up the band.

Hmmm...it's been theorized that the aliens working with the missing Nazi U-boats have often utilized 70.775 as an analog sideband control channel for the amanati...

Admiral Byrd was also swept by a beam at 70.450 that caused the immediate ending and recall of Byrds 1948 mapping mission in the Antarctic. Which purportedly is where the submarines are hiding, and UFO's are often seen...

DJ-MichaelAngelo wrote: ↑

Wed Nov 29, 2023 12:25 pm

Are there any stores still left in the Grand Rapids area that sell these 75/300 ohm adapters, where I can buy them in person? I miss Radio Shack! lol -- I know I can order them super cheap online, but it'd be nice to have a local source where I can purchase and have them immediately, not wait days for shipping. I did try Best Buy but no luck there.

Hi DJ,

Menards shows having both those items, branded as RCA, for $3.99 each. In stock at both the Comstock Park and Clyde Park Ave. stores.

Possibly some of the area Ace Hardware stores will have one or both as well.

If you want to support a local shop, check out T & W Electronics at 1045 S Division. Weekdays only 8am-5pm per my last trip there. Not sure if they have these specific items, but they're my go-to for 300 twin lead to 75 ohm coax baluns with weather boots, so long as they still have them in the back. What I've purchased there have solid copper leads, versus stranded or crimped-on ends.

Regarding Radio Shack, Downtown Greenville still has the vacant storefront with the Radio Shack sign in place from years ago. Up North, Charlevoix has (or had) a very traditional one still open as of late 2020 when I stopped in and purchased a couple 90 degree F connectors. It felt very nostalgic.

Cheers! ~~ Statmanmi