What my restorations involve.
Operation: Antennas: Most of the early sets will require an antenna to operate, if they have an internal antenna it is stated in the Ad.
The ground connection is no longer necessary as that is done thru the power cord on grounded chassis sets. Antennas can range from a 6 foot length of wire which will pick up local stations to several hundred feet looped around a wall or attic or strung out to a tree for distant stations or exceptional short wave performance.Normally I recommend 50 feet of wire run inside the house as any external antennas much have lightening protection.There are also "active" antennas on the market that can be purchased which will sit on the set top and amplify the signal before it is even fed in thru the antenna input on the set.Textbooks have been written on antenna design so if you wish to use your newly purchased antique radio for distant listening it might be worth researching.
Single runs of wire used for an antenna should connect directly to the antenna connection "A".Loops of wire used for an antenna should be connected between the antenna connection "A" and ground or on sets with an "A" and "Z" antenna connection between the "A" and "Z" with the coupling between the "Z" and ground connection removed or disconnected.
Auxiliary inputs: Some of my more current restorations do include an Auxiliary input, this can be used with and Aux cord to a phone or other device to inject audio into the audio stage of the radio if the circuit design permits, then you just switch it to auxiliary input, tune away from a station and listen to the outside audio. Some circuit designs allow for use of the radios volume control and others do not, you would then use your devices volume control. I do not guarantee how loud the volume would be with an outside device or any interference that might occur, they are tested with a borrowed android phone and not guaranteed performance wise with others, im not a smartphone guy and don’t have the time or inclination to delve into it any farther. For sets without the Auxiliary input I do have a way for purchasers to listen to something other than constant repeats of the same commercials and to the music of their choice on their antique radios, small AM transmitters such as the “Talking house” or the “ SSTRAN AMT3000” are available in either kit or pre-assembled and ready to go form, this is then connected to your device and the radio tuned to an empty spot on the dial for listening. This is not only a non-invasive way of doing things but this one transmitter will work on any and all of the sets in your collection individually or all at the same time. You will find this cheaper than paying to have even 2 sets modified from other restorers. This device can be found in many online locations such as Ebay, Amazon and others.