75 ohm antenna connection ''disappeared''

I don't know but will take a guess - I expect the radio is a vintage am/fm transistor radio. The am antenna is likely to be a ferrite rod tuned directional type that will be inside the cabinet.

The fm antenna might be a single core wire that dangles from the set in the way commonly used by many fm radio-alarm clock-radios. This performs the same function as the single telescopic antenna of portable radios without the cost and similarly is connected internally to the first rf stage. Sometimes due to age, mishandling or ignorance the dangling wire is lost or cut off.

A higher quality table radio (not designed to be portable) is equipped with a facility to connect a 300 ohm balanced antenna, a 75 ohm fm antenna or both.

The 300 ohm type connects to a pair of screws accessible at the rear without removing any covers and is usually an indoor type. The 75 ohm type plugs in with a standard coax plug and could be either an indoor type or an outdoor type.

A matching transformer is available to use a 75 ohm antenna with a 300 ohm input. The 300 ohm type is highly directional in horizontally polarised signal areas and is not always convenient to use.

INSTALLATION

Channel Master by PCT indoor antennas are designed to provide optimum reception of

UHF / VHF and FM signals. These antennas have 75 ohm outputs, which allow simple,

hassle-free connections to today's newer TV sets that have 75 ohm F type connector

inputs.

Simply attach one end of the supplied 6' cable with F connectors to the output of the

antenna (Fig.1). Attach the other end of the cable to the input of the TV set or VCR

(Fig. 2). Some adjustment of the antenna might be necessary for optimum viewing.

Model CM-4030 includes a built-in amplifier and separate power supply.

1. Follow the same steps as above for antenna to TV / VCR hookup. Note : Model

CM-4030 also allows for two set / VCR hookups with its unique dual output feature.

2. Insert the power injector into the back of the antenna (Fig. 3). Plug in the power
transformer to the closest electrical outlet (Fig. 4).

Google 4030 Channel Master Instruction Sheet for the PDF File with the diagram.

Fig 2a
Fig 3 Fig 4

prohibido por ley.

TV

Fig 1 VCR

Fig 2

Fig 2a
Fig 3 Fig 4

Radio Shack has an
adapter catalog number 278-0291. It takes some effort to push the 278-0291
adapter onto the FM UNBL 75 ohm terminal so wait until you have the 278-0291
installed before you connect your 75 ohm coax on to your new adapter.

This will resolve your FM screw on F connector antenna interface issue.


I see others trying to
help suggest using a 300 ohm to 75 ohm transformer match unit, this isn't what is needed. Your receiver antenna input IS a 75
ohm input.

On ebay?

External FM antennas can be had for as little as $7 for the a simple dipole version (looks like a "T") to a highly directional outdoor type for over $150 at your local Radio Shack below:

http://www.radioshack.com/search/index.jsp?kw=fm&f=Taxonomy/RSK/2032189&categoryId=2032189&kwCatId=2032057&fbc=1&filterName=Category&fbn=Taxonomy/Antennas

The simple $7 dipole is a "twin lead" 300 ohm type that many home stereos shipped with because they are inexpensive, take up little room in the box and work surprisingly well for all but the very distant of stations. These antennas are also found for sale in many department and some hardware stores too. Your stereo may not offer twin lead or 300 ohm hook ups (2 terminal screws near the ANT label) but only a 75 ohm connection (like your cable tv connections), in which case, you'll need an inexpensive 300 to 75 (terminal to cable) ohm balun (or matching transformer) like this one below:

http://www.amazon.com/Parts-Express-Push-On-Balun/dp/B0002ZPIOQ

or to go the other way - from 75 to 300 (cable to terminal) ohm balun like this one:

http://www.amazon.com/75-300-Ohm-Matching-Transformer/dp/B0002ZPIOG/ref=pd_bxgy_e_text_c

Please rate this reply if you found it helpful. Good luck!

1. Check for any loose connections starting at your TV. (Coaxial cables unscrew themselves with vibration...) Check all outdoor connections for corrosion and cut off and replace any cable ends that show corrosion.

2. Check your alignment - (positioning or pointing)
http://www.wowvision.tv/OTAalignment.htm

3. Replace the balun a.k.a. 75 ohm matching transformer.

If these don't work, a larger antenna is needed...

with one exception:

That exception is if your signal is too high. If this is the case, change alignment to reduce signal a little.

Yes you have a defective laser assembly. The 139 is a great price as buying the laser lens alone will cost you around 70 .Bose will also upgrade with any new software and will also provide you with a 1 yr warrenty.

Product Specs: General: Product Type Radio antenna Recommended Use Indoor Width 3 in Depth 16.9 in Height 3.5 in Color Black Localization English Antenna: Wave Band AM, FM / FM: 87.5 - 108 MHz, 540 - 1700 kHz Impedance 75 Ohm Gain Level 42 dB Amplifier Built-in Included Accessories Connector coupler, impedance transformer Connections: Connector Type 1 x FM antenna ¦ 1 x AM antenna Power: Power Device Power adapter - external Manufacturer Warranty: Service & Support 1 year warranty Service & Support Details Limited warranty - 1 yearlet me know how this works out for u

Hold the alarm setup button and at the same time hit the on/off button.

The fix for the problem is simply go to Radioshack and purchase their part number 278-267 which is an "F" jack to 1/8" Male Plug. The cost is $6.09. This should solve your problem. The 75-Ohm antenna plug can now be screwed or connected to the "F" connector.