[TenTec] TT 940 Power Supply

[denton sprague]

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 at 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 at 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 at 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 at oregontrail.net>
>>> To: "Discussion of Ten-Tec Equipment" <tentec at 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 at 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 at 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 at contesting.com
>>>>> http://lists.contesting.com/mailman/listinfo/tentec
>>>>> 
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