The Zenith Royal 810 was deemed 'The Symphonette' was considered a 'coat pocket' size portable radio. First released in 1966 this nine-transistor AM-FM radio was designed in the US but made in Korea or Japan. It shared the same printed board chassis (9NT41Z8) as the almost identical Royal 51 radio. It is powered by four AA batteries but also has a power input jack on the rear for a 6-volt adapter which could be purchased separately as a Zenith accessory.
The kit came with a leatherette case and strap, an earphone, and instructions. The radio has an internal ferrite core antenna for AM and an external telescoping whip antenna for FM. Sound comes from a 45 ohm 2.75 inch Alnico permanent magnet speaker with a dynamic moving coil. Undistorted power output is 100 milliwatts.
The band switch has three options: AM, AFC, and FM. The AFC (Automatic Frequency Control) is for FM. The lock-in range for the AFC circuit is 760 kHz at 50 micro-volts.
Frequency ranges:
AM (540-1600 kHz)
FM (88-108 MHz)
Sensitivity:
AM - Approximately 200 microvolts / meter for 50 milliwatts output above noise.
FM - Approximately 3 microvolts for 50 milliwatts output.
This radio was working when I received it, but had weak reception for some stations. I cleaned it thoroughly and performed alignments for AM and FM as specified by the Zenith Service Manual. It now plays well across both bands. The leatherette case had a small tear in it at the snap - which seems to be a common thing. I repaired that and applied mineral oil to the case and strap to soften and preserve them.
Dimensions: 8 x 6 x 4 inches
Weight: 2.6 lbs.
See demo on Instagram here: www.instagram.com/reel/C38iJusShNl/
See detailed demo on YouTube here: youtu.be/-ZYyPTnv_54
The kit came with a leatherette case and strap, an earphone, and instructions. The radio has an internal ferrite core antenna for AM and an external telescoping whip antenna for FM. Sound comes from a 45 ohm 2.75 inch Alnico permanent magnet speaker with a dynamic moving coil. Undistorted power output is 100 milliwatts.
The band switch has three options: AM, AFC, and FM. The AFC (Automatic Frequency Control) is for FM. The lock-in range for the AFC circuit is 760 kHz at 50 micro-volts.
Frequency ranges:
AM (540-1600 kHz)
FM (88-108 MHz)
Sensitivity:
AM - Approximately 200 microvolts / meter for 50 milliwatts output above noise.
FM - Approximately 3 microvolts for 50 milliwatts output.
This radio was working when I received it, but had weak reception for some stations. I cleaned it thoroughly and performed alignments for AM and FM as specified by the Zenith Service Manual. It now plays well across both bands. The leatherette case had a small tear in it at the snap - which seems to be a common thing. I repaired that and applied mineral oil to the case and strap to soften and preserve them.
Dimensions: 8 x 6 x 4 inches
Weight: 2.6 lbs.
See demo on Instagram here: www.instagram.com/reel/C38iJusShNl/
See detailed demo on YouTube here: youtu.be/-ZYyPTnv_54