[hpsdr] FW: HERMES TX OUTPUT

[Doug Ronald]

Why not simply make your own splitter? Here is one design I found with a
simple search. It has good isolation between ports, and low loss. There
should be a small trimmer from the autotransformer's output to ground to
compensate for leakage inductance, but the correction is small, and can be
left out as this person did...
https://www.qsl.net/va3diw/power%20splitter.html
 
Here is another one, higher power:
https://www.w6pql.com/1_8_to_54_mhz_combiner_set.htm

73, Doug, W6DSR

-----Original Message-----
From: Hpsdr [mailto:hpsdr-bounces at lists.openhpsdr.org] On Behalf Of George
Byrkit
Sent: Friday, June 21, 2019 08:42
To: hpsdr at lists.openhpsdr.org
Subject: [hpsdr] FW: HERMES TX OUTPUT

***** High Performance Software Defined Radio Discussion List *****

So this is the dialog that I had off-list with Tony.  Posting back so that
you know that he's aware of all these issues.
And some of these items are often available on eBay, too.  They may be
surplus, but they are still fit for purpose!

73,
George K9TRV

-----Original Message-----
From: George Byrkit <ghbyrkit at chartermi.net>
Sent: Friday, June 21, 2019 9:17 AM
To: 'Tony Hagen' <prosdr at gmail.com>
Subject: RE: [hpsdr] HERMES TX OUTPUT

Tony,
It would be about $100 if you bought 10 pieces, or if you buy their 'demo'
board.

But then, there is the ZSC-2-2+, 2-way Connectorized Power Splitter,
0.002-60MHz, Connector Type: BNC That sells for $53 on the website.
Packaged, mounted, connectorized, ready to go.  That might be a good choice.

73,
George K9TRV

-----Original Message-----
From: Tony Hagen <prosdr at gmail.com>
Sent: Friday, June 21, 2019 8:49 AM
To: George Byrkit <ghbyrkit at chartermi.net>
Subject: Re: [hpsdr] HERMES TX OUTPUT

ok then I ready wrong on the cost side - I thought its would be 100$

Yes, ADP2 will work as well as I need only 2 inputs. Fine, thank you very
much Now I will figure out



73
Tony
-----Original Message----- 
From: George Byrkit
Sent: Friday, June 21, 2019 6:05 PM
To: 'Tony Hagen'
Subject: RE: [hpsdr] HERMES TX OUTPUT

Tony,
I would think that the mini-circuits part would do fine.  A bit of loss
compared to the active buffer, but not too expensive ($10 in quantity 10
from minicircuits.)  The downside might be availability, unless you already
have one or have a source that will provide/sell only one.  The other
downside is the 5db loss to each output.

If you don't really need the 3rd output of that part, I'd consider the ADP-2
products.  For example, the ADP-2-1+ costs less, and is available in their
EZ-sample program.  It's also .5mhz to 400mhz, and only 3db loss.  But only
handles .5w in.  The ADP-2-1W+ will handle 2w in, but only goes down to 1
MHz, but up to 650 MHz.

That's one family of parts I'd like to see Minicircuits give away (or so
cheaply it's almost a give-away) at Dayton.  They often have some wonderful
things there.  Best if you are a vendor, also, and can see what they have
when they set up on Thursday.  And get them before other people discover
them.

73,
George K9TRV

-----Original Message-----
From: Tony Hagen <prosdr at gmail.com>
Sent: Friday, June 21, 2019 8:12 AM
To: George Byrkit <ghbyrkit at chartermi.net>
Subject: Re: [hpsdr] HERMES TX OUTPUT

Hello George,

Yes, a unity gain buffer stage is certainly will be a good option - which I
have not thought of earlier.

I was thinking for splitter - may be this - which is of course going to be
expensive  https://ww3.minicircuits.com/pdfs/AD3PS-1+.pdf

In any case would this above splitter approach of mini circuits will be ok ?


73
Tony
-----Original Message----- 
From: George Byrkit
Sent: Friday, June 21, 2019 5:24 PM
To: 'Tony Hagen' ; hpsdr at lists.openhpsdr.org
Subject: RE: [hpsdr] HERMES TX OUTPUT

Tony,
That sounds like it could be very sketchy if you don't have a proper
splitter at the output of the Hermes, to split the power to two amplifiers.
This would also help isolate each amp from the other, and lessen the
back-effect on Hermes, and on each other amp's input.

If I were doing this seriously, I would place a (overall unity gain) buffer
stage in between the Hermes, that is designed to split the signal and
provide significant isolation. Likely this is 3 op-amps.  One to buffer the
output of the Hermes, with build-out resistors to the input of each buffer.
Buffer should be designed for 50 ohms in and out.

For an example, take a look at the schematic of the TADD-1, by John
Ackermann, N8UR, offered by TAPR.
http://www.tapr.org/~n8ur/TADD-1_Manual.pdf
Schematic is at the end.  It may not be broad band enough for your purpose,
but it should give you the idea.

73,
George K9TRV

-----Original Message-----
From: Hpsdr <hpsdr-bounces at lists.openhpsdr.org> On Behalf Of Tony Hagen
Sent: Friday, June 21, 2019 7:25 AM
To: hpsdr at lists.openhpsdr.org
Subject: [hpsdr] HERMES TX OUTPUT

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