Copper Talk » Open Forum » Archived Messages » 2003 » 05/01/2003 to 05/31/2003 » Radio QRP - The Art of Low Power « Previous Next »

Author Message
Top of pagePrevious messageNext messageBottom of page Link to this message

R_QRP
Posted on Thursday, May 08, 2003 - 6:20 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Mostly wanted: A very basic transmitter using MOSFET (IRF510) for any form of broadcasting in the 40 mb.

You will find more information about this concept here: http://www.geocities.com/radio107mhz/

We are searching for any manufacturer or supplier of a basic 12 volt DC powered AM short-wave transmitter and would like some feedback as to what is available on the US/European market i.e.: power/price. The transmitter should be oriented to the low market segment and have desirable features in this price segment. Our requirement is a good basic transmitter with discrete components and with MOSFET (IRF510) design that can run up to 5-10 watt output with crystal clear full mod. Designed with modulator and transmitter in a robust metallic box and constructed with the philosophy of rugged simplicity and functionality. Transmitter should be built with available and inexpensive components. Good for any form of clandestine operations in the 40 mb in rough terrain. The transmitter should be based on The Grenade Transmitter concept made by Radio Animal (WKND) and preferred requirements are:

# Compact size for portable operation. 12 volt powered. Solid state and designed according to a philosophy of rugged simplicity and functionality with available and inexpensive components.

# Ruggedness: The transmitter should be designed to withstand abrupt load mismatch errors or inadvertently disconnection from the transmitter. Robust and foolproof design for use in rough terrain.

# Aprox. 5-10 watts output fully modulated.

# Integrated low pass filtering.

# X-tal operated (VXO) despite crystals are getting rare

# Line level input with switcheable audio transformer for higher levels.

# Accurate schematic and component list should be included with the transmitter, to make repair and adjustment easy. Constructed with common discrete components

Any manufacturer or supplier is welcome to contact us: fmtx@euroseek.com

You will find more information about this concept here: http://www.geocities.com/radio107mhz/

Thanks!
Top of pagePrevious messageNext messageBottom of page Link to this message

Tech833
Posted on Thursday, May 08, 2003 - 11:07 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

What you are asking for, you have already answered on your web page.

Although I could easily design and build such a transmitter for you, I don't think I could do it for less than $2K. The transmitter you mention on your website for under $100 would be more cost effective for you.
Top of pagePrevious messageNext messageBottom of page Link to this message

Sandbagger106
Posted on Thursday, May 08, 2003 - 1:09 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I worked a station, on 1.818 running about 100 miliwatts. That's my version of QRP. sb106.
Top of pagePrevious messageNext messageBottom of page Link to this message

bruce
Posted on Thursday, May 08, 2003 - 1:59 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

QRP ?

hummmmm like my htx-200 it may be too late for me but you wouln't scramble brain cells with it!