[TenTec] OT: SDRplay ???

Jim Brown k9yc at audiosystemsgroup.com
Fri Dec 16 13:27:59 EST 2016

Hi guys,

I bought the RSP-1 several months ago, primarily to use as test 
equipment. I haven't really put it through its paces in a serious way, 
but it is clearly worth the $130 I paid for it from HRO.

Overload is easily solved by inserting a simple pad (resistive voltage 
divider) at the input. As a genuine old fart, I have at least one 
excellent commercial product that is switchable in steps, as well as a 
box full of fixed value attenuators.

FWIW, I don't think that shielding has anything to do with degrading 
performance unless internal circuit layout is poor. The most common 
causes of poor rejection of interfering signals is poor circuit layout 
and the "Pin One Problem" (failure to properly terminate the cable shield).

The "10 MHz" reference is to the maximum span width that can be 
displayed, and it's 9 MHz without images. The primary value of this is 
when chasing RFI -- it means that it could be used to study RFI from 1.8 
- 10.8 MHz (or 3.5 - 12.5 MHz) with a single setup.

SDR receivers like this can also be used for the occupied spectrum 
measurements I've been doing on modern radios. My prior work has been 
with an Elecraft P3, looking at the 8.8 MHz IF of a K3S as a front end. 
That unit has excellent frequency resolution (as narrow as a few Hz when 
using the SVGA board), but the dynamic range is only 100 dB, and only 
80d dB can be displayed on screen.

A comparison of low cost SDR receivers for use in chasing RF noise can 
be seen on a series of slides beginning with #31  in this set used for a 
talk I gave at Pacificon in October.


Another option is the FunCube Dongle Pro. I bought one and started 
playing with it a day or so before giving the talk.

With all of these products, what you can do with them depends VERY 
strongly on what software you use on your computer to control them. 
There are a half dozen or so of these programs, each of which has its 
strengths and weaknesses for any given use.  All I've seen are freeware. 
Simon Brown is the author of one package, currently in its second or 
third generation. His work is uniformly very good.

This survey is also quite useful. 

The first of these radios that I  bought for use as a spectrum analyzer 
is the ANAN 10e. I have no interest in using it as a ham rig -- I'm 
quite happy with my K3s. :)  Last I heard, N1EU is a happy ANAN user.

73, Jim K9YC

On Fri,12/16/2016 8:27 AM, Mike Pagel wrote:
> The SDRPlay RSP2 was introduced recently and includes several upgrades 
> over the original version, including a layer of RF shielding inside 
> the case.  A data sheet is online at 
> http://www.sdrplay.com/docs/RSP2_Datasheet.pdf .  As I understand it 
> the price for the new model is at $169 and the original unit (RSP1) 
> has dropped to $129
> I've been thinking about getting one of these to serve as a panadapter 
> for the Orion but am also concerned about overload problems when used 
> with conventional antennas.  Is overloading a real concern?  If so, 
> how is it solved?
> 73, de Mike, K9UW
> ------ Original Message ------
> From: "Martin Sole" <hs0zed at gmail.com>
> To: tentec at contesting.com
> Sent: 12/16/2016 8:12:59 AM
> Subject: Re: [TenTec] OT: SDRplay ???
>> I have one and like it a lot, great tool for noise hunting as well. 
>> There are options to turn the gain down which helps in some overload 
>> situations. If you want to see the full 10Mhz bandwidth at once you 
>> will need USB3, USB2 will be awful choppy at more than about 2MHz. I 
>> have seen a website/YTV(youtube video) where someone rebuilt one into 
>> a metal enclosure for better immunity. Also saw lining the case with 
>> copper foil done. Nothing is perfect but at the price point it's a 
>> lot of radio for little money and with its other tool like 
>> functionality it's more than just a radio.
>> Martin, HS0ZED
>> On 16/12/2016 13:26, rick at dj0ip.de wrote:
>>> Tnx Barry,
>>> I was reading eham reports (which I don't value very high) but there 
>>> seemed
>>> to be a lot of complaints about overloading on large antennas.  Mine 
>>> will be
>>> on an all band dipole so it picks up plenty of signal from lots of 
>>> bands.
>>> I can use a preselector with it, I have a couple.
>>> One thing I read that makes sense though I don't know if it is true, 
>>> was one
>>> should never place a direct conversion RX in a plastic enclosure.
>>> 73 - Rick, DJ0IP
>>> (Nr. Frankfurt, Germany)

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