Ramsey Electronics FT146 manual

Page 25

NOTE ON REPLACEMENT PARTS:

If you lose or damage parts during assembly or testing, you may, of course, order any needed replacement parts by writing or faxing the Ramsey Electronics, Inc. factory. Some of the more common parts may also be picked up at Radio Shack or other local parts distributors. Use EXACT values when replacing parts. The following is a general guide to obtaining parts for your transceiver as quickly as possible:

[A]: Radio Shack or local electronic parts distributor: Resistors, electrolytic capacitors, disc capacitors, common NPN or PNP transistors, zener diodes, switching diodes, hookup wire, LED, controls, antenna and microphone connectors.

[B]: Order from RAMSEY ELECTRONICS: Most RF and VHF transistors, coils, crystals, PIN diodes, varactor diodes, trimmers, IC chips.

[C]: U1 is a common dual op-amp made by many manufacturers and is commonly stocked by most parts stores. There are also acceptable "standard replacements" for some of the semiconductors used in the transmitter. "SK" and "ECG" standard replacements are stocked by local electronics parts distributors or may be ordered through a Radio Shack store. The following chart should help you make the most cost-effective choice if replacement semiconductors are needed. Performance of your transmitter will, in most cases, not be up to full spec if you decide to use a relacement device, but will get you by in a pinch.

Part ID

Type

Recommended source

 

 

RE=Ramsey, RS=Radio Shack

Q1, etc.

2N3904

RS 276-1617

Q12,13,14

PNP 221334

RS276-1604 or 2N3906

Q2, etc.

2SC2498

ECG10, SK9139, 2N5179, or RE

Q3

NE021

MRF901 or RE

Q9

2N3866

ECG311, SK3195 or RE

Q8

SD1127

MRF237, ECG341, SK9617 or RE

D

1N4148

1N914, RS276-1620 (pack of 50)

D3,D23

BB505

RE

D18

1N4002

RS276-1102, 1N4003

D11,D12

6.2 V zener

RS276-561

U1

LM358

ECG928, SK3691 or RE

FT146 • 25

Page 24 Page 26
Image 25
Page 24 Page 26
Contents Meter FM 5 Watt Transmitter KIT Ramsey Transmitter Kits FT146 FM Receiver KIT Introduction FT146 Circuit Description Capacitors FT146 2 Meter FM Transmitter KIT Parts ListResistors and potentiometers Semiconductor devices Inductors and ferrite coresSpecial components Required, not suppliedRamsey Learn-As-You-Build KIT Assembly FT146 FT146 FT146 Resisto Test point loopPC board Procedure as used above for these coils. Each coil Winding L3 and L4 Use the same wireEnameled wire Is 2 1/2 turns and will appear to be 3 turns ifFT146 FT146 Wire jumper Wire sits flat FT146 Short lead here TESTING, Alignment and AdjustmentFT146 Verifying Transmitter RF Output Your Power Supply and RF Output PowerFT146 Troubleshooting Hints Maximizing RF Power OutputMicrophone Considerations Crystal Requirements Other Enclosure RecommendationsFT146 FT146 Parts Layout Diagram Ramsey Kit Warranty Required Tools Estimated AssemblyTotal Solder Points Time

FT146 specifications

The Ramsey Electronics FT146 is a versatile and compact FM transmitter that stands out for its user-friendly operation and impressive performance in both amateur and professional audio applications. Designed for hobbyists, educators, and small businesses alike, the FT146 offers a reliable solution for broadcasting audio signals over a short to moderate range.

One of the main features of the FT146 is its simple plug-and-play setup, which allows users to get started quickly without needing extensive technical knowledge. The device operates with a frequency range of 88.1 to 107.9 MHz, covering the entire FM broadcast band. This flexibility enables users to choose the best frequency for minimal interference in their transmission area. Additionally, with an adjustable output power of up to 2 watts, the FT146 can effectively cover distances ranging from a few hundred feet to several miles, making it ideal for a variety of broadcasting scenarios.

The FT146 utilizes advanced modulation technology to ensure high-quality audio transmission. It supports monophonic audio, which is perfect for clear voice and music transmission. The integrated audio limiter prevents distortion, ensuring that the sound quality remains consistent, even at higher volumes or varying audio signals.

Another notable characteristic of the FT146 is its robust construction. Housed in a durable metal enclosure, the transmitter is built to withstand everyday use. The compact design allows for easy portability, making it suitable for field applications, on-location broadcasting, or as a permanent installation in a small venue.

In terms of connectivity, the FT146 features multiple audio input options, including a 3.5mm jack and RCA inputs. This versatility allows users to connect various audio sources, such as MP3 players, computers, or professional-grade audio equipment.

Furthermore, the FT146 also includes an LED power indicator and a built-in antenna output for enhanced transmission efficiency. Users can either connect an external antenna for increased range or utilize the included telescopic antenna for convenience.

Overall, the Ramsey Electronics FT146 combines ease of use with professional-grade features, making it an excellent choice for anyone looking to explore FM broadcasting. Whether for personal projects, educational purposes, or small business promotions, the FT146 delivers reliable performance and adaptability in a compact package.
Top Page Image Contents