Equipment for VHF and UHF

Transceivers

The question of which transceiver to buy can be perplexing. Here is a list of current models by the Big 3 manufacturers, with abbreviated specifications:    Current VHF/UHF Rigs

Linear amplifiers

• Options for Higher Power on 144, 432 and 1296MHz

So you've decided to add a VHF/UHF linear amplifier to your station. Transistors or Valves? How much power? Which valve is best? Buy one or build it yourself? Click here for some notes on a talk given by VK2KU in April 2002 to the NSW VHF Dx Group:    RF Power Options 

• The AM-17 Amplifier on 144MHz

  Ian Cowan VK1BG has collected together a series of modifications to the AM-17 Amplifier for operation on 144MHz.
  Click here to read or download Ian's notes:    Notes on the AM-17 Amplifier
  

• Russian Tubes

  There is no doubt that tubes from the Russian domestic market represent the best value for money when building your own Linear Amplifier, and these are now available from a number of sources. For a comprehensive list of tube types and specifications, together with references to a large number of actual amplifiers built with them, visit the following websites:

  http://www.nd2x.net/base-1.html
  http://www.df6na.de/

• Basic Amplifier Designs for 144 and 432MHz

By all means design your own Linear Amplifier, but here are 3 well-known designs:

W1SL - a classic push/pull design for 2 tubes on 144MHz, first presented in QST in 1971, but described in detail in Chapter 8 of the Green Book*, also in Chapter 4 of the VHF/UHF Handbook*.

W2GN - a parallel tube design for 2 tubes on 144MHz, first presented in Ham Radio in 1977, but described in detail in Chapter 4 of the VHF/UHF Handbook*.

K2RIW - a parallel tube design for 2 tubes on 432MHz, first presented in QST in 1972, but described in detail in Chapter 10 of the Green Book*.

• Parts for Linear Amplifiers

Here are some possible sources of parts for building your linear amplifier:

Surplus Sales of Nebraska:    http://www.surplussales.com/SSIndex.html
RF Parts:    http://www.rfparts.com

• Power Supplies for Valve Linear Amplifiers

For a comprehensive discussion of the design of anode and screen supplies, with particular emphasis on safety of the HV supply and proper voltage regulation of the screen supply, see Chapter 11 of the Green Book*.

* The Green Book - "The VHF/UHF Dx Book", edited by Ian White G3SEK, published by DIR Publishing Ltd (England) in 1992.
* The VHF/UHF Handbook, edited by Dick Biddulph G8DPS, published by the RSGB (England) in 1997.

We plan further pages/links on:

• VHF Rigs vs Transverters

• Preamps on 144, 432 and 1296MHz

• Calibration points on S-meters

• Sequencing of Relays for T/R switching

• Sources of Components in each State