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Microwave Equipment for the Ham Bands

This page started as a thread on the [Mw] mailing list:

Microwave mailing list

http://www.valinet.com/mailman/listinfo/microwave

The question was relative to the best way to get started on the microwave bands when one only has a limited budget.

David M. Upton WB1CMG had this to say, feel free to add any useful information you may have (Click the “Edit” button below):


VHF/UHF:

Can't argue with the advice to get on 6 and 2 meters first and start making acquaintances locally. Maybe you will find some others similarly inclined and start racing each other to add bands or get away from the crowd. I would then strongly suggest adding 222 capability most likely with a transverter and then 432. Once this base is established there are some real shortcuts and bargains out there where the bands overlap or share with other commercial developments. The principal component where one sees this is amplifiers but you never know when attending the fleas or cruising the 'Bay what will show up at any time. Here are some suggestions for microwave on the cheap with elbow grease application sometimes necessary:

903:

Amplifiers for the band are abundant and cheap coming out of Cellular service. Be sure they are linear and not Class C (FM only) types which will be true if used for CDMA or other modern service. Be prepared to supply +26 V at quite a few amps to keep these happy. Outputs from 50W-200W are available readily and require practically no modification.

Preamps from tower installations are also quite common and cheap, < $40 or so.

1296:

Despite lots of attempts to popularize the band by the Yaecomwood trio, not much stands out here for hamming on the cheap. Some of the 900 preamps may have gain at 1296 but are not guaranteed. These must be tested. PAs are available from DEMI in the 40W range that are reasonably affordable but not too easy to build.

2304:

This is currently the mother lode of ham conversions of commercial surplus. First, amplifiers from PCS service at 1900 have been converted to 2304 successfully and written up in the Eastern Microwave Conference proceedings on at least a couple of occasions. These are available to hams for a nominal fee unconverted. WA1HCO's website has details of fairly simple conversions for these to get to 2304 MHz. Also, these amps do operate at 12 V in a reduced power mode. They do require drive of a few Watts. Contact MGEF members for details.

There are also lots of preamps, antennas, connectors and other stuff showing up from various nearby commercial activities. The Wi-Fi 802.11 stuff is not terribly useful as it is too highly integrated unless the components can be taken off the board and separated.

3456:

Amplifiers are the big thing here. Pyrojoseph on the Bay has these or had these running 40W or so for $150 and hundreds are probably out there. They had very high gain to match so a few mW drive was all that was needed.

Don't overlook old C-band TVRO preamps/converters when looking for preamps and parts. Big Ugly Dishes (BUDs) can often be had from homeowners for the asking once you spot a Ku-band dish on their roof.

5760:

Sort of the odd man out, at least in my experience. Components are available to roll your own as surplus from various wireless ventures but you have to be lucky and in the right place at the right time. Preamps and Amps predominate along with the occasional brick oscillator for feeding into a mixer.

10G:

There has been a lot of interest in this band for a very long time. Components are available and surplus items often in waveguide form will work just fine. Brand new designs of equipment on this band are becoming very affordable with serious capability. Power that was unheard of just a few years ago is now relatively commonplace.

Solid-state 8 W amplifiers are common among the better equipped stations at about $300 each from DEMI. These particular units need a Watt or so of drive. TVRO Ku-band dishes and preamps will work well here particularly if salvaged from some older satellite units (pre DirectV or Echostar-Dish). Gunnplexer rigs running FM are out there but I would consider these pretty limiting for the lone amateur. Much better off in a group of enthusiasts if using these. Don't be afraid to start at low power levels on 10 GHz if you go mountain-topping. Even a few mW initially will probably work if the other station knows where you are and has a comparable dish. Brick oscillators as the core frequency determining component of your station are also readily available. Older transverters exist too but beware of issues with hard to obtain parts. Many people got on the band with the so-called white box conversions or Qualcomm boards surplus and re-tuned for 10G. There was also a 1W PA board that many people use locally.

24G:

Once again, Pyrojoseph on the 'Bay has been known to have amplifiers on this band capabler of 300 mW or more which is a lot of power. These are not plug and play and will require bias circuits to be built around them but are not terribly expensive-around $100. This band marks the spot where everything starts to get difficult. Good machining skills or waveguide components are the preferred way to go here. W2PED makes an amplifier from scratch that is also pretty nice but somewhat more pricey. Both amps I mentioned have high enough gain so very little drive is required and noise figures are sufficient as to enable use as an LNA as a means to get started. A very nice YIG-stabilized LO is available from Norm Gillaspie that outputs signals at either 13 or 26 GHz. The Ku-band dishes (the smaller ones) can be used on this band with the appropriate feeds made up and fitted. See the w1ghz.org online antenna book for this information. Getting accurate frequency calibration is a major problem on this band and so many different LO approaches are used.

Setting up a station is non-trivial and everything costs money-even the simplest fittings and connectors. Careful planning to minimize interconnects in your set-up can help minimize costs and improve reliability.

There you have a list of some ways to do Microwaves on the cheap. Let your intuition run wild when given that hunk of surplus stuff-who knows what you can figure out how to make use of it?

 
ham_radio/microwave_equipment_for_the_ham_bands.txt · Last modified: 2013/01/08 19:00 (external edit)
 
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