Carrier freq of 9000.0 USB, filter center freq of 9001.5
Stock 2400Hz filter, filter center freq of 9001.5, filter passband
9000.3-9002.7KHz --> audio passband 300-2700Hz
Inrad 2800Hz filter, filter center freq of 9001.5, filter passband
9000.1-9002.9KHz --> audio passband 100-2900Hz
This is with stock carrier oscillator alignment
I've done this as an experiment on Corsair II and Omni VI and
performed as expected, although I reinstalled the 2.4KHz filter
afterwards.
73, Barry N1EU
On Tue, Oct 1, 2013 at 1:38 AM, Bob McGraw - K4TAX <RMcGraw@blomand.net> wrote:
> The data I provided is from the Tentec alignment procedure for the two
> radios.
>
> The carrier is not in the middle of the passband of the filter, otherwise if
> so, one would have a DSB signal not a SSB signal Thus to swap sidebands,
> the BFO frequency must change to the opposite side of the filter and is
> placed down the slope some 3 dB to 6 dB.
>
> Carrier frequency + / - the modulated audio frequency produces two
> sidebands, one of which is eliminated by the filter.
>
> 73
> Bob, K4TAX
>
>
>
> ----- Original Message ----- From: "Barry N1EU" <barry.n1eu@gmail.com>
>
> To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
> Sent: Monday, September 30, 2013 11:58 AM
>
> Subject: Re: [TenTec] TenTec Paragon II model 586,
>
>
>> Maybe my math is wrong, but I figure a passband of 100 Hz to 2900 Hz
>> with the 2.8 KHz filter with its center frequency of 9001.5 KHz.
>>
>> Yes, the carrier suppression/null alignment should be carefully
>> performed after installing the new filter, but it's not a difficult
>> procedure. I would follow that with on-air tests to verify inaudible
>> carrier levels.
>>
>> 73, Barry N1EU
>>
>> On Mon, Sep 30, 2013 at 4:37 PM, Bob McGraw - K4TAX <RMcGraw@blomand.net>
>> wrote:
>>>
>>> The carrier oscillators are not centered in the filter but are typically
>>> at
>>> the edge or somewhat down the slope of the filter edge. And usually down
>>> the slope some 3 dB to 6 dB with the oscillators being switched in
>>> frequency
>>> to the upper edge or lower edge of the filter depending on mode.
>>>
>>> In the case of the Omni VI Plus the oscillators switch to produce LSB and
>>> USB signals with oscillator frequency being 9.000000 MHz for LSB and
>>> 9.003000 for USB and CW transmit/Tune being 9.000400 MHz. Thus the
>>> filters
>>> are some 600 Hz down the slope of the filter.
>>>
>>> With the Paragon the oscillator frequencies are 9.000000 for USB and
>>> 9.003000 MHz for LSB and RTTY and 9.000700 MHz for CW/Tune mode.
>>>
>>> I don't see much if anything to be gained by changing the transmit
>>> bandwidth
>>> from 2.4 KHz to 2.8 KHz. Thus the audio frequency response would be
>>> about
>>> 300 Hz to 2700 Hz with the 2.4 KHz filter and 300 Hz to 3100 Hz with the
>>> 2.8
>>> KHz filter.
>>>
>>> Another factor to be considered is the carrier suppression as the carrier
>>> is
>>> positioned on the slope of the filter. If the filter response is not
>>> correct, the shape factor not correct and the slope of the filter not
>>> correct, be assured that carrier suppression will likely suffer as the
>>> filter does contribute to overall carrier suppression.
>>>
>>> My take on changing filters..........nice science project.
>>>
>>> 73
>>> Bob, K4TAX
>>>
>>>
>>>
>>>
>>>
>>>
>>> ----- Original Message ----- From: "Mike Bryce" <prosolar@sssnet.com>
>>> To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
>>> Sent: Monday, September 30, 2013 10:32 AM
>>> Subject: Re: [TenTec] TenTec Paragon II model 586,
>>>
>>>
>>>
>>>> bill,
>>>>
>>>> the same filter is used for BOTH transmit and receive.
>>>>
>>>> I have not put one in, but it's a simple matter of un-plugging the old
>>>> one and pushing the new in its place.
>>>>
>>>> most of the time that's all you need to do, but sometimes you need to
>>>> touch the carrier oscillators to make sure they're are centered in the
>>>> filter.
>>>>
>>>> remember, at 2.8khz, you'll won't be a popular fellow on a crowded band
>>>>
>>>>
>>>> Mike, WB8VGE
>>>> SunLight Energy Systems
>>>> The Heathkit Shop
>>>> http://www.theheathkitshop.com/
>>>> J e e p
>>>> o|||||||o
>>>>
>>>> A man with one clock knows what time it is. A man with two clocks is
>>>> never
>>>> sure.
>>>>
>>>>
>>>>
>>>> On Sep 30, 2013, at 10:12 AM, Basilie Actipis wrote:
>>>>
>>>>> Has anybody out there have put the inrad 2.8khz SSB filter in their
>>>>> paragon
>>>>> for TX????????
>>>>> Where is the TX SSB filter is located??????
>>>>> I know I can use the 6khx AM filter for RX,but I will also install one
>>>>> for
>>>>> RX.
>>>>> Thank you in advance for the help.Bill / N1ASS.73..............
>>>>>
>>>>> I am re-posting so others have returned from the TT hamfest can read
>>>>> and
>>>>> see if anybody has a answer. Thank you.
>>>>> --
>>>>> *73........Bill / N1ASS.*
>>>>> _______________________________________________
>>>>> TenTec mailing list
>>>>> TenTec@contesting.com
>>>>> http://lists.contesting.com/mailman/listinfo/tentec
>>>>>
>>>>
>>>> _______________________________________________
>>>> TenTec mailing list
>>>> TenTec@contesting.com
>>>> http://lists.contesting.com/mailman/listinfo/tentec
>>>>
>>>
>>>
>>> _______________________________________________
>>> TenTec mailing list
>>> TenTec@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/tentec
>>
>> _______________________________________________
>> TenTec mailing list
>> TenTec@contesting.com
>> http://lists.contesting.com/mailman/listinfo/tentec
>>
>
>
> _______________________________________________
> TenTec mailing list
> TenTec@contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|