[TenTec] Omni VI

Tue Oct 2 10:50:29 EDT 2018

The reason I wanted you to do the experiments was to eliminate other routes for coupling of various digital signals into the receiver.

Ten Tec had LOTS of problems with this sort of thing. The undesired coupling of signals into the receiver input.

This was often caused by coax cables passing through holes in the Aluminum chassis, a situation in which the chassis becomes the secondary of a small transformer and the coax is the primary. In order to alleviate this, Ten Ten placed pieces of insulating (white, double sided acrylic foam) tape between the inner covers and the chassis hole edges through which cables passed. 

If any of these are missing or in bad condition, you might experience this sort of problem.

Have a look at every place where coax passes through a chassis wall. Replace any missing or damaged pieces of tape with foam tape from the hardware store. Leave the release liner in place on the side that faces the removable sheet metal that touches these pass-through holes. Your intent is to break the closure of the hole that occurs when the sheet metal is installed.

Another source of this type of problem can be electrolytic capacitors. You don’t have to replace them all, or even remove them all for testing. You can do a test in which you use an external known-good cap, about 100 uF and 25 volt rated, with the negative connected to chassis with a short wire (no more than 4 inches or so). Go around the radio and ground each end of every electrolytic you see, one-at-a-time, and see if the click-while-tuning effect goes away.

If you find a capacitor where this takes place, then move the external capacitor to the other lead of the faulted capacitor to see if the effect is the same on both ends. If not, then the capacitor is bad.

The reason you only hear this on high bands is that the conversion scheme is different on the high bands than on the low bands so the harmonics and mixing products that show up in the radio are different on high bands compared with the low bands.

Gary

> On Oct 1, 2018, at 7:20 PM, Byron Cordes via TenTec <tentec at contesting.com> wrote:
> 
> Ok tried aux ant  . There is a very slight noise when turning vfo probably wouldn’t even notice if 20 meters wasn’t just about dead! So probably diodes . Anyone know of good replacements?
>   Can anyone  explain  what was going on there? I’m really at loss.  Thanks 
> 
> Sent from my iPad
> 
>> On Oct 1, 2018, at 6:58 PM, Byron Cordes via TenTec <tentec at contesting.com> wrote:
>> 
>> Ok pulled connection 17 on front end board. Turn vfo nice and quiet , no more click sound with vfo turning!
>> So we look at low pass filter board ?? Boy there’s not much there I guest try aux ant ? 
>> 
>> Sent from my iPad
>> 
>>> On Oct 1, 2018, at 7:38 AM, Byron Cordes via TenTec <tentec at contesting.com> wrote:
>>> 
>>> Ok I’ll do that tonight. Thanks for the help I really appreciate it. Byron
>>> 
>>> Sent from my iPad
>>> 
>>>> On Sep 30, 2018, at 10:01 PM, MadScientist <dukeshifi at comcast.net> wrote:
>>>> 
>>>> Pull cable marked “17” from the RF front end board and do the same test.
>>>> 
>>>> Gary
>>>> f
>>>>> On Sep 30, 2018, at 7:33 PM, Byron Cordes via TenTec <tentec at contesting.com> wrote:
>>>>> 
>>>>> Ok I pulled 9mhz filter and no more noise when vfo turned. Put 9mhz back in and pulled 6.3 and noise stopped. So noise coming out of mixer? 
>>>>> 
>>>>> Sent from my iPad
>>>>> 
>>>>>> On Sep 29, 2018, at 3:48 PM, Byron Cordes via TenTec <tentec at contesting.com> wrote:
>>>>>> 
>>>>>> Yes rx is ok and tx is ok . You can’t hear anyone from the clicking noise till you stop turning the vfo and when you stop it rx fine. 
>>>>>> 
>>>>>> Sent from my iPad
>>>>>> 
>>>>>>> On Sep 29, 2018, at 3:45 PM, MadScientist <dukeshifi at comcast.net> wrote:
>>>>>>> 
>>>>>>> OK, but, when this is happening, the radio still works fine (good TX and RX), right?
>>>>>>> 
>>>>>>> Gary
>>>>>>> 
>>>>>>>> On Sep 29, 2018, at 3:44 PM, Byron Cordes via TenTec <tentec at contesting.com> wrote:
>>>>>>>> 
>>>>>>>> Radio has a click sound with each number on frequency readout when vfo knob turned. This is on 20meters and higher. 40 -160 works normally. 
>>>>>>>> Will look at radio again tomorrow night. 
>>>>>>>> 
>>>>>>>> Sent from my iPad
>>>>>>>> 
>>>>>>>>> On Sep 29, 2018, at 2:04 PM, MadScientist <dukeshifi at comcast.net> wrote:
>>>>>>>>> 
>>>>>>>>> Please explain this issue a bit more.
>>>>>>>>> 
>>>>>>>>> I am not clear of the meaning of the description "clicks for each number “.
>>>>>>>>> 
>>>>>>>>> Do you mean you hear a click in the speaker or what?
>>>>>>>>> 
>>>>>>>>> Dose the radio otherwise work on the higher bands?
>>>>>>>>> 
>>>>>>>>> Gary
>>>>>>>>> 
>>>>>>>>>> On Sep 25, 2018, at 8:51 PM, Byron Cordes via TenTec <tentec at contesting.com> wrote:
>>>>>>>>>> 
>>>>>>>>>> Hi everyone 
>>>>>>>>>> I have a Omni VI that I’m down to one last problem.
>>>>>>>>>> On 20 meters or higher  when you turn the VFO the radio clicks for each number . Anyone have any idea? 
>>>>>>>>>> Thanks Byron AC9PA 
>>>>>>>>>> 
>>>>>>>>>> Sent from my iPad
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