[NLRS] 6GHz microwave stuff

[Dr. Gerald N. Johnson]

6 Ghz bricks can be handy for doubling to 12 for half frequency 
injection for 24 Ghz, though the bricks are fairly common. The power 
amps probably have most of the bandwidth of the TWTs they replaced and 
so should be very good at 5.6 GHz. The spec is 5.9 to 6.4 because that's 
their band allocation, not that the hardware won't cover a wider range.

On the other hand, RFMD now has some 5mm square devices that for 
receiving includes the LNA and an image rejection mixer with internal 
phase shifting, so all it needs is an LO and simple RF filtering. The TX 
device which puts out 50 mw includes the image reject mixer so it needs 
the same LO and filtering. Four devices cover 5 to more than 24 GHz. The 
highest frequency chips use half frequency LO with built in frequency 
doublers. The parts are about $50 each, way more than their weight in gold.

As far as useful parts, PA, LO, filters probably can be retuned to 5.76 
Ghz, circulators, feed horns, waveguide elbows and runs are probable all 
useful. My interest is very low however.

On 8/6/2012 8:00 PM, Doug Reed wrote:
>
>
> I'll be helping some friends scrap out an old microwave relay site over
> the next few weeks or month. It has a lot of waveguide based equipment
> that I'll be taking and scrapping out for parts. It is all marked as
> being in the 5.9-6.4GHz band. The waveguide filters cover twelve 40MHz
> channels within the band. What I can see includes a lot of microwave
> brick oscillators and waveguide components of all sorts.
>
> Does anyone want to try building a rig or a beacon from these parts? A
> 6.2GHz brick LO with a 440MHz driver might work.... Any one of the
> bricks with a SI570 oscillator and rigged for QRSS or PSK31 or JT65
> might work better. Or FM modulate the brick itself?

Usually a small step in supply voltage produces adequate FSK for beacon 
service.
>
> Most of it is Northern Telcom model RD-6C digital microwave receivers
> and transmitters. There is also some older generation, Rockwell- Collins
> MW-109E-1. Both models are solid state up through the power amps. The
> equipment all runs on -24 volts DC or on lower internally regulated
> voltages.
>
> The NT is listed as .5, 1, or 2 watts output, depending on model. The
> Collins was originally either 5 or 10 watt TWTs but they have been
> replaced with solid state amps and I don't know their power out. If
> anyone knows if the amps will cover the 5.6GHz band, let me know. Since
> they are spec'ed down to 5.9-6.4GHz, they may work down to 5.6GHz....
> I've got manuals for most of the pieces too.
>
> NT brick is NT1H98xx DRO phase-locked oscillator +16dBm output
> NT RF pwr amp is NT1H63BA or B or C
>
> There is a lot of WR137 waveguide coming out too. The waveguide will be
> sold for copper scrap value. If there is any specific fitting, bend,
> piece, or length of waveguide that you might need for some project, let
> me know and maybe I can save it for you. There are many pieces over 3'
> long so if you want to make a slot antenna, now is your chance to get
> the materials.
>
> One other thing you can make with old waveguide is interdigital filters.
> Several years ago I made a nice filter for 1240-1300MHz based on a
> section of WR229 and the design charts from the ARRL Microwave Handbook.
> I used brass hobby tubing and drilled matching holes in the tubing,
> measured and cut the brass elements a bit long, then marked the correct
> length and slide it into the holes. I did use a sweeper for final
> alignment but it was pretty close based only on measurements. Yes, pipe
> cap filters are a lot smaller and easier to tune, but will not be as
> durable or handle as much power as the waveguide version. :-)
>
> I'll know more by Wednesday and will probably have some parts removed to
> look at by then. If you've got a suggestion for anything I should be
> looking for, let me know.
>
> We'll also be removing the old open frame relay racks. They will go to
> scrap unless someone asks for one. These are telco standard, a base
> about 18" deep x 19" wide with vertical 6" channel uprights about 7'
> high. All drilled and threaded for 19" relay panels. They will support a
> ton of weight although you will need to bolt the base to the floor or
> the tops to a rafter if you don't want it to fall over.... :-)

Or load the KW PA power supply at the bottom and the microwave IF at the 
top.

73, Jerry, K0CQ
>
> 73, Doug Reed, N0NAS.
> ______________________________________________________________
>