[hpsdr] 31db attenuator

[Helmut]

Funny Glen! My national distributor offers DAT-31A-SP+ (5 Bit, 1 dB step) at
25 pieces minimum quantity. Maybe someone on the list has spares availanle.
Good luck.

73, Helmut, DC6NY


-----Ursprüngliche Nachricht-----
Von: K4KV [mailto:k4kv at k4kv.com] 
Gesendet: Dienstag, 4. April 2017 14:44
An: Helmut; 'hpsdr'
Betreff: Re: AW: [hpsdr] 31db attenuator

Helmut,


My point is that you CANNOT get the 31db part any more!  At least I 
cannot find any.

So, we are now stuck with the 6-bit part, and I do not know what to do 
about it.  I am able to

change the code myself, but the learning curve would be steep.  I have 
written C code for more than

20 years, but that is a long way from FPGA Quartus programming with no 
experience!

;-)

73

Glen K4KV



On 4/4/2017 08:29, Helmut wrote:
> Glen, I don't believe that you will get happy with a 0.5 dB version.
Correct
> S-meter reading or automatic PS-feedback-adjustment probably need 1 dB
> steps.
>
> 73, Helmut, DC6NY
>
> -----Ursprüngliche Nachricht-----
> Von: Hpsdr [mailto:hpsdr-bounces at lists.openhpsdr.org] Im Auftrag von K4KV
> Gesendet: Dienstag, 4. April 2017 13:43
> An: hpsdr
> Betreff: [hpsdr] 31db attenuator
>
> ***** High Performance Software Defined Radio Discussion List *****
>
> Hello,
>
> I have been struggling for some time with the rx attenuator on my
> hand-built Hermes boards.  I felt like the
>
> mini-circuit part never worked correctly.  I just got in some brand new
> chips and replaced the chip.  No
>
> difference!
>
> I got both the old and the new data sheets.  The new part is the
> DAT-31R4A SP+
>
> It is 6-bit and in 0.5db steps.  The original part is 5-bit and in 1 db
> steps.
>
> So, it is my contention, that this could never work correctly. The only
> part that is available is the new part, the
>
> 6-bit part.
>
> The reason I verified this is that I got an older Hermes board that was
> factory built and repaired it.  It has the old
>
> mini-circuits part, and works as it should.
>
>
> Can someone make me a version of Hermes code, or can we make a version
> that supports both the 5-bit and 6-bit
>
> parts?  I did not get that deep into the programming of the chip, but it
> may be as simple as always sending a 6
>
> bit code, and moving the old 5-bit data to the end.
>
> 73
>
> Glen K4KV
>
>
>
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