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Re: [TenTec] TT 940 Power Supply

To: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Subject: Re: [TenTec] TT 940 Power Supply
From: denton sprague <denton@oregontrail.net>
Reply-to: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Wed, 17 Sep 2014 09:02:31 -0700
List-post: <tentec@contesting.com">mailto:tentec@contesting.com>
an update…..I strapped my Omni 7's ground to the negative line to my Astron 30 
amp switching supply….I also installed two ferrite clamp on chokes on the dc 
lines on the inside of the power supply.

80 mtrs noise…s5
60 mtr noise…..s4
40 mtr noise…..s4
30 mtr noise…..s3
20 mtr noise…..s4
17 mtr noise…..s4..s6 growl at 18.158 mh…not really noticeable this time.
18 mtr noise…..s3-4
12 mtr noise…..s3
10 mtr noise…..s3
Only antenna change is I am now using my LL tuner (dual roller inductor) 
transmatch to match the twin lead.
Since the LL tuner is not shielded, it is prone to picking up rf noise in the 
shack…
Also…bands are wide open today….




On Sep 2, 2014, at 1:24 PM, denton sprague <denton@oregontrail.net> wrote:

> an update….
> Since the bands are pretty much trash this afternoon, I did power supply seat 
> of the pants consideration…
> Rig…TT omni 7, rf gain 100 percent, no rf attenuation…
> Antenna…80 mtr horizontial loop up 30 ft, 8 ft of rg8x to 4 to 1 current 
> balun on window sill, then 400 ohm ladder line to antenna…no transmatch in 
> circuit.
> TT 940 sits just to the right of the rig….moving it is not an option as I am 
> hearing impaired and it needs to be right in front of me.
> 
> here are noise readings from power supplies..
> 
>               Astron 30SS     TT 940  Astron 50m
> 80 mtrs       S7                      S7(1)   S5
> 60 mtrs       S4                      S6              S4
> 40 mtrs       S5                      S5              S6(band noise came up a 
> bit?)
> 30 mtrs       S5                      S3              S3
> 20 mtrs       S4                      S4              S4
> 17 mtrs       S4                      S5-6    (2)     S4
> 15 mtrs       S3                      S3              S3
> 10 mtrs       S1-3                    S3              S1-3
> 
> (1) 3.873 S7 growl from TT 940 noticeable
> 
> (2) 18.158 S7 growl from TT 940 noticeable
> 
> Since I normally run 18 db of attenuation and rf gain at about 40 percent on 
> 80 mgr ssb, I did not notice any growl from the 940 after strapping the rig 
> and power supply together.
> 
> On Sep 2, 2014, at 10:36 AM, denton sprague <denton@oregontrail.net> wrote:
> 
>> Ok….I installed a no 10 wire between power supply and Omni 7….that seems(?) 
>> to have cured the problem.
>> No chopped the 3rd pin ground….I got everything in the shack tied to a 
>> industrial grade sine wave ups running on a dedicated 20 amp circuit.
>> speaker is on the right of the rig….also have a little astron ss30 and a 
>> huge astron 50m linear power supply that I used to use for entire station. 
>> No rf hash for any of the laptop chargers so far…
>> On Sep 2, 2014, at 10:13 AM, "Bob McGraw - K4TAX" <RMcGraw@Blomand.net> 
>> wrote:
>> 
>>> Do you have a solid ground wire between the supply and the radio?  If not 
>>> the radio is about 1/8 to 1/4 volt above DC ground.
>>> 
>>> You haven't chopped the 3rd pin ground have you?   For safety reasons, it 
>>> must be in place.
>>> 
>>> Some have reported with the supply on the left it makes noise, on the right 
>>> it does not.  I may have my left's and right's reversed.  Anyway, I think 
>>> you get the idea.
>>> 
>>> The ONLY noise I have from a switching supply is from the charger for my 
>>> laptop computer.  I've purchased three different ones.  All produce noise.
>>> 
>>> As to the station supply, I use Astron SS-30M's or SS-25's.  Have three and 
>>> all are quiet.
>>> 
>>> 73
>>> Bob,  K4TAX
>>> 
>>> 
>>> 
>>> 
>>> ----- Original Message ----- From: "denton sprague" <denton@oregontrail.net>
>>> To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
>>> Sent: Tuesday, September 02, 2014 10:43 AM
>>> Subject: Re: [TenTec] TT 940 Power Supply
>>> 
>>> 
>>> Well darn…
>>> my 940 has a traveling growling noise on 80 meters….wonder if there is an 
>>> easy fix?
>>> Otherwise will sell the darn thing….
>>> On Aug 29, 2014, at 11:36 AM, Ralph Arnold <rea.papaof10@gmail.com> wrote:
>>> 
>>>> I'm interested in PS for my Pegasus will it handle it and how much $$ 73
>>>> KD8BTQ  Ralph
>>>> 
>>>> 
>>>> On Fri, Aug 29, 2014 at 1:17 PM, Charles J. Nagel <cnagel@sbcglobal.net>
>>>> wrote:
>>>> 
>>>>> I have four TT switching power supplies I use for various rigs including
>>>>> Ten-Tec and Elecraft. Never a noise issue. One is a recently acquired 940,
>>>>> a perfect match for the Omni VII, in my opinion.
>>>>> 
>>>>> Charles, K0CW
>>>>> _______________________________________________
>>>>> TenTec mailing list
>>>>> TenTec@contesting.com
>>>>> http://lists.contesting.com/mailman/listinfo/tentec
>>>>> 
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