[MAMS] 5.7 GHz rainscatter question

Thu Aug 9 10:04:47 EDT 2012

Based on the QST article (October 1990, page 27) the board that Danny 
has is purely bidirectional, there's a MMIC frequency doubler for the 
LO, a RF port and an IF port. No switching for a transceiver on the IF 
and no antenna switching for low sensitivity and low power.

73, Jerry, K0CQ

On 8/9/2012 8:28 AM, mary boller wrote:
> Hi Danny. That 5760 is set up with relays that are already installed that switch from t ransmit to receive. YOu can actually use the thing by hooking the dish up to the output relay. I put one SMA relay on the input side and one on the output side. When I got the thing in order to go from receive to transmit you had to unhook the sma connectors and swap them out, so I put the relays in to take care of it. Just hooking the dish to it at my neighbors house gave me EN 40, the 144 transverter that is built in handles everything else. You get someone close enough it will blow your ears off. Talk to Randy and see if he might have an amp, he has had them in the past
>
>
>
> ________________________________
>   From: Danny Pease<dpease at adams.net>
> To: geraldj at weather.net; 'Mid-America Microwave Society'<mams at mailman.qth.net>
> Sent: Wednesday, August 8, 2012 5:49 PM
> Subject: Re: [MAMS] 5.7 GHz rainscatter question
>
> You are right Jerry, the mixer is followed by a filter, no amplifiers of any
> sort after the mixer output probably lucky to be -10 dBm. It will need a
> couple of stages to get up to 1 watt, probably 3 or 4 if I add more
> filtering. I am guessing the 18 inch offset feed dish I have at maybe 25 dB
> of gain, so even a 1 watt output still is pretty low ERP. I am still on the
> lookout for a free 2 to 3 foot dish, but one that size is a bit harder to
> hold up for portable use. I have a place nearby that has one of the farm
> data dishes in the front yard, I may eventually get that one, no one has
> lived in the house for a few years now, so I know it is not being used.
>
> Danny
>
>
> -----Original Message-----
> From: mams-bounces at mailman.qth.net [mailto:mams-bounces at mailman.qth.net] On
> Behalf Of Dr. Gerald N. Johnson
> Sent: Wednesday, August 08, 2012 12:38 PM
> To: mams at mailman.qth.net
> Subject: Re: [MAMS] 5.7 GHz rainscatter question
>
>
>
> On 8/8/2012 12:12 PM, Danny Pease wrote:
>> I see I can get a couple of boards and devices from a seller on Ebay
>> for 1 watt out for a very reasonable price, but I was pretty sure that
>> 1 watt and the 18 inch dish I have would be a little on the weak side
>> plus having to split the single output of the transverter into
>> separate TX and RX for the amplifier and preamp, meaning a decent pair of
> relays or PIN diode switches.
>> I am getting a little antsy to try this stuff out and I am pretty sure
>> the few milliwatts I have available won't get me too many QSO's from
>> around here.
>>
>> Danny NG9R
>> EN40la
>>
>>
> Bigger dishes aren't difficult to acquire. Look for a 30" at a farm that
> used to get data from DTN on KU satellite. Or Channel Master dishes are sold
> on line at reasonable prices (though any price is infinitely greater than
> free).
>
> Can the Tx and Rx lines be separated inside the transverter, and their
> combining relay moved outside? The only case of them being inherently
> combined thatt I can think of is seeing the mixer directly which means poor
> receiver sensitivity and minuscule Tx power.
>
> Sometimes suitable relays can be had at reasonable prices like from Hangar
> 18 Surplus. The may take 28 volts though.
>
> 73, Jerry, K0CQ
> ______________________________________________________________
> MAMS mailing list
> Home: http://mailman.qth.net/mailman/listinfo/mams
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:MAMS at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
> ______________________________________________________________
> MAMS mailing list
> Home: http://mailman.qth.net/mailman/listinfo/mams
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:MAMS at mailman.qth.net
>
> This list hosted by: http://www.qsl.net/
> Please help support this email list: http://www.qsl.net/donate.html
> ______________________________________________________________
> MAMS mailing list
> Home: http://mailman.qth.net/mailman/listinfo/mams
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:MAMS at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>