Radio Preppers

General Category => Technical Corner => Topic started by: gil on July 24, 2012, 09:17:55 PM

Title: The Retro-75 AM 75m Transceiver Kit.
Post by: gil on July 24, 2012, 09:17:55 PM
Hello,

Another success! I got a Retro-75 from Small Wonder Labs and a nice blue case from TenTec, put the whole thing together in a couple days. It works. 75m AM is good for regional communications, but requires a very long antenna... I haven't built one yet. That's around 120ft of wire, if I am not mistaking. The quality of AM voice is great.

(http://radiopreppers.com/images/Retro75.jpg)

The Retro-75 is crystal controlled, with two crystals of your choice on the board. That's what the A/B switch is. Transmit is keyed by switch or press-button. It is extremely simple to operate. Output power is 3W.

That's what I love about kits, they will give you a working transceiver for often less than $100, capable of long distance contacts. That way you're not eating into your other prepping supplies budget.

Gil.
Title: Re: The Retro-75 AM 75m Transceiver Kit.
Post by: raysills on August 30, 2012, 03:51:32 PM
Another neat transceiver from Small Wonder Labs.  Even though antennas are long... 125 feet or so for a dipole, you can still get effective use by mounting it fairly low to the ground... say 15 or 20 feet from the surface.  When at that height above ground, the antenna will be operating in NVIS mode (New Vertical Incidence Skywave)... which sends most of your signal "straight up", when it bounces back from the lowest level of the ionosphere, and sort of "floods" the area around you within 100 miles or so, with your signal.

Military communications often use that mode for communicating to the "other side of the mountain", when VHF line-of-sight propagation won't do the job.  A benefit is that you don't receive interference from long distant signals that would normally be received if the antenna were mounted up high.. like 50 feet or more.

73 de Ray
K2ULR
Title: Re: The Retro-75 AM 75m Transceiver Kit.
Post by: gil on August 30, 2012, 04:07:59 PM
Hello Ray,

I sold that radio, maybe a mistake.. Now I do have 80m on the K2 and K1, though not AM... I made a W3EDP antenna, which should work for 80m, we'll see. I djust don't have a tree high enough to try it at the house here..

Thanks for your comments about the K2  :)

Gil.