Elecraft

K3: Main RX gone deaf

Classic

List

Threaded

11 messages Options

Udo Langenohl - DK5YA

K3: Main RX gone deaf

Gentleman,

I'm struggling with a Main RX vs. Sub RX issue. My Main RX is rather
deaf compared to the Sub RX. I see at least 23.5dB attenuation between
Main RX and Sub RX when comparing highly stable signals from my signal
generator (HP8664A). This is only for ANT1/2 vs. AUX-IN!
Example:
-33dBm on 28.500
into AUX-IN (SUB RX): exactly 59 +40dB
into ANT 1 (Main RX): 59 +15dB
into ANT 2 (Main RX): 59 +15dB

I've checked all the usual suspects (pin diodes):
D1 and D5 on the KXV3A: o.k.
Each and every pin diode on the SUB IN board: o.k.
D5 on the Main RX board: o.k.

This is a K3 #59xx with almost everything inside money can buy.

My second K3 (serial #39xx) does not show this strange behavior. Main RX
and SUB RX show exactly the same values on ANT1/2 and AUX IN. -33dBm is
59+40 on MAIN and SUB RX, no matter if Ant1, 2 or AUX IN.

Any idea? I'm searching for weeks now and I'm close to give up.

Udo, DK5YA
--
******************************************
Webs by DK5YA: *
http://www.mmmonvhf.de/ [editor]*
http://www.vhfdx.de/ [owner] *
http://www.palekastro.de/ [owner] *
http://www.solweb.de/ [owner] *
http://www.spessartwetter.de/ [owner] *
******************************************

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

Gary Smith-2

Re: K3: Main RX gone deaf

Udo,

I'm not one of the more knowledgeable
people on the list and hopefully, somebody
with better knowledge than me helps you
more. But with that, this is what I would
look at if it were my radio...

1. Are your crystal filters set up
properly; Could they be in reverse order
between slots 1-5 on the main board and
sub receiver?

If they are in the identical order, have
you set the K3 up to know what crystals
are in there and, do you have the order of
the crystals correct using the K3 Utility?
If you have one bank listed opposite in
the filter configuration, this will not
work properly.

2. When Using B set; do you have the
filters set the same on both Sub & main?

Do you have the antennas set properly for
the main as well as sub Rx? Could your
main antenna for RX be listening to the
wrong antenna?

It's good you have two K3's: What you
might do is have both of the K3's you
have, side by side and check each setting,
comparing the known good one to the
settings on the one you're having trouble
with.

3. Have you tried your good radio in place
of your K3 that has the issues?
Conversely, have you tried your problem K3
in the location your good K3 is? Perhaps
there is a problem with the coax or
antenna connections?

Hopefully you will find your answer
without having to have anything repaired.

73 & Happy hunting,

Gary
KA1J

> Gentleman,
>
> I'm struggling with a Main RX vs. Sub RX issue. My Main RX is rather
> deaf compared to the Sub RX. I see at least 23.5dB attenuation between
> Main RX and Sub RX when comparing highly stable signals from my signal
> generator (HP8664A). This is only for ANT1/2 vs. AUX-IN!
> Example:
> -33dBm on 28.500
> into AUX-IN (SUB RX): exactly 59 +40dB
> into ANT 1 (Main RX): 59 +15dB
> into ANT 2 (Main RX): 59 +15dB
>
> I've checked all the usual suspects (pin diodes):
> D1 and D5 on the KXV3A: o.k.
> Each and every pin diode on the SUB IN board: o.k.
> D5 on the Main RX board: o.k.
>
> This is a K3 #59xx with almost everything inside money can buy.
>
> My second K3 (serial #39xx) does not show this strange behavior. Main RX
> and SUB RX show exactly the same values on ANT1/2 and AUX IN. -33dBm is
> 59+40 on MAIN and SUB RX, no matter if Ant1, 2 or AUX IN.
>
> Any idea? I'm searching for weeks now and I'm close to give up.
>
> Udo, DK5YA
> --
> ******************************************
> Webs by DK5YA: *
> http://www.mmmonvhf.de/ [editor]*
> http://www.vhfdx.de/ [owner] *
> http://www.palekastro.de/ [owner] *
> http://www.solweb.de/ [owner] *
> http://www.spessartwetter.de/ [owner] *
> ******************************************
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

Gary Smith-2

Re: K3: Main RX gone deaf

In reply to this post by Udo Langenohl - DK5YA

Elecraft mailing list

Re: K3: Main RX gone deaf

In reply to this post by Udo Langenohl - DK5YA

GM Udo,
What if you use your Rx IN port, is it the same thing?I've had the same problem a few weeks ago,almost no rx on ANT 1 or ANT2, normal rx on AUX-IN-SUB RX but normal rx on RX input from KXV3A and it turned out to be D26 from the RF board.Give it a try:-).
Good luck!
BobYO8RNI

From: Udo Langenohl - DK5YA <[hidden email]>
To: [hidden email]
Sent: Sunday, April 24, 2016 10:53 PM
Subject: [Elecraft] K3: Main RX gone deaf

Gentleman,

I'm struggling with a Main RX vs. Sub RX issue. My Main RX is rather
deaf compared to the Sub RX. I see at least 23.5dB attenuation between
Main RX and Sub RX when comparing highly stable signals from my signal
generator (HP8664A). This is only for ANT1/2 vs. AUX-IN!
Example:
-33dBm on 28.500
into AUX-IN (SUB RX): exactly 59 +40dB
into ANT 1 (Main RX): 59 +15dB
into ANT 2 (Main RX): 59 +15dB

I've checked all the usual suspects (pin diodes):
D1 and D5 on the KXV3A: o.k.
Each and every pin diode on the SUB IN board: o.k.
D5 on the Main RX board: o.k.

This is a K3 #59xx with almost everything inside money can buy.

My second K3 (serial #39xx) does not show this strange behavior. Main RX
and SUB RX show exactly the same values on ANT1/2 and AUX IN. -33dBm is
59+40 on MAIN and SUB RX, no matter if Ant1, 2 or AUX IN.

Any idea? I'm searching for weeks now and I'm close to give up.

Udo, DK5YA
--
******************************************
Webs by DK5YA: *
http://www.mmmonvhf.de/   [editor]*
http://www.vhfdx.de/   [owner] *
http://www.palekastro.de/   [owner] *
http://www.solweb.de/   [owner] *
http://www.spessartwetter.de/   [owner] *
******************************************

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

Graham Kimbell

Re: K3: Main RX gone deaf

In reply to this post by Udo Langenohl - DK5YA

Hi Udo
Before you start tearing the rig apart, two ideas:-

-is there a big difference for weak signals of say S4?
-if not, it may just be the S meter calibration that needs attention.
-if so, preamp on for either? Att on for main?

HTH
Graham

On 19:59, Udo Langenohl - DK5YA wrote:

Udo Langenohl - DK5YA

Re: K3: Main RX gone deaf

Gentleman,

thanks for all so many replies. Will try to check all ideas tomorrow,
XYL permitting ... ;-).

73 Udo, DK5YA

P.S.: The issue occurs at the RX IN and TVTR IN ports of the KXV3A too.

Am 25.04.2016 um 17:57 schrieb Jerry:

> Reseat the internal coax jumpers in the surf signal path.
>
> Sent from my iPad
>
>> On Apr 25, 2016, at 11:52 AM, Graham g3tct <[hidden email]> wrote:
>>
>> Hi Udo
>> Before you start tearing the rig apart, two ideas:-
>>
>> -is there a big difference for weak signals of say S4?
>> -if not, it may just be the S meter calibration that needs attention.
>> -if so, preamp on for either? Att on for main?
>>
>> HTH
>> Graham
>>
>>> On 19:59, Udo Langenohl - DK5YA wrote:
>>> Gentleman,
>>>
>>> I'm struggling with a Main RX vs. Sub RX issue. My Main RX is rather deaf compared to the Sub RX. I see at least 23.5dB attenuation between Main RX and Sub RX when comparing highly stable signals from my signal generator (HP8664A). This is only for ANT1/2 vs. AUX-IN!
>>> Example:
>>> -33dBm on 28.500
>>> into AUX-IN (SUB RX): exactly 59 +40dB
>>> into ANT 1 (Main RX): 59 +15dB
>>> into ANT 2 (Main RX): 59 +15dB
>>>
>>> I've checked all the usual suspects (pin diodes):
>>> D1 and D5 on the KXV3A: o.k.
>>> Each and every pin diode on the SUB IN board: o.k.
>>> D5 on the Main RX board: o.k.
>>>
>>> This is a K3 #59xx with almost everything inside money can buy.
>>>
>>> My second K3 (serial #39xx) does not show this strange behavior. Main RX and SUB RX show exactly the same values on ANT1/2 and AUX IN. -33dBm is 59+40 on MAIN and SUB RX, no matter if Ant1, 2 or AUX IN.
>>>
>>> Any idea? I'm searching for weeks now and I'm close to give up.
>>>
>>> Udo, DK5YA
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to [hidden email]
>
>

Elecraft mailing list

Re: K3: Main RX gone deaf

Then you should check also D25 from the RF board.The easiest way to find out the problem is to inject signal at different point in the rx chain and see where it stops working, or where it starts working,hi!
Good luck!BobYO8RNI

From: Udo Langenohl - DK5YA <[hidden email]>
To: Jerry <[hidden email]>; Graham g3tct <[hidden email]>
Cc: [hidden email]
Sent: Monday, April 25, 2016 11:02 PM
Subject: Re: [Elecraft] K3: Main RX gone deaf

Gentleman,

thanks for all so many replies. Will try to check all ideas tomorrow,
XYL permitting ... ;-).

73 Udo, DK5YA

P.S.: The issue occurs at the RX IN and TVTR IN ports of the KXV3A too.

Am 25.04.2016 um 17:57 schrieb Jerry:

--
******************************************
Webs by DK5YA: *
http://www.mmmonvhf.de/   [editor]*
http://www.vhfdx.de/   [owner] *
http://www.palekastro.de/   [owner] *
http://www.solweb.de/   [owner] *
http://www.spessartwetter.de/   [owner] *
******************************************

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

Udo Langenohl - DK5YA

Re: K3: Main RX gone deaf

In reply to this post by Udo Langenohl - DK5YA

Gents,

I had another test session today with my K3 and here's what I've done
and what happened:

1. I've checked all the test points recommended by Elecraft. No issue
found, all stages are working, there's noise increasing on each test
point at the Main RX.

2. Fired up my signal generator again and started on the Main RX with a
signal on the following frequencies and with these results:

Filter settings: 2.7KHz
Preamp off
Att: no
Signal strength: -63 dBm
Mode: USB

28.130 = S6
21.130 = S6
18.130 = S4
14.130 = S2 (!!)
10.130 = S4
7.130 = S8 (!!)
3.513 = S6

Same settings at the Sub RX (via AUX IN):

28.130 = S9+5
21.130 = S9+10
18.130 = S9+10
14.130 = S9+10
10.130 = S9+5
7.130 = S9+10
3.513 = S9+10

You will see that there are dramatic differences at the Main RX from
band to band and from S2 (14 MHz) up to S8 (7 MHz). And of course when
comparing Main RX with Sub RX. Also tried different filter settings (AM,
CW), no change.

I have no idea what is happening here and what to do next.

73 Udo, DK5YA

Am 25.04.2016 um 22:02 schrieb Udo Langenohl - DK5YA:

> Gentleman,
>
> thanks for all so many replies. Will try to check all ideas tomorrow,
> XYL permitting ... ;-).
>
> 73 Udo, DK5YA
>
> P.S.: The issue occurs at the RX IN and TVTR IN ports of the KXV3A too.
>
> Am 25.04.2016 um 17:57 schrieb Jerry:
>> Reseat the internal coax jumpers in the surf signal path.
>>
>> Sent from my iPad
>>
>>> On Apr 25, 2016, at 11:52 AM, Graham g3tct <[hidden email]> wrote:
>>>
>>> Hi Udo
>>> Before you start tearing the rig apart, two ideas:-
>>>
>>> -is there a big difference for weak signals of say S4?
>>> -if not, it may just be the S meter calibration that needs attention.
>>> -if so, preamp on for either? Att on for main?
>>>
>>> HTH
>>> Graham
>>>
>>>> On 19:59, Udo Langenohl - DK5YA wrote:
>>>> Gentleman,
>>>>
>>>> I'm struggling with a Main RX vs. Sub RX issue. My Main RX is rather
>>>> deaf compared to the Sub RX. I see at least 23.5dB attenuation
>>>> between Main RX and Sub RX when comparing highly stable signals from
>>>> my signal generator (HP8664A). This is only for ANT1/2 vs. AUX-IN!
>>>> Example:
>>>> -33dBm on 28.500
>>>> into AUX-IN (SUB RX): exactly 59 +40dB
>>>> into ANT 1 (Main RX): 59 +15dB
>>>> into ANT 2 (Main RX): 59 +15dB
>>>>
>>>> I've checked all the usual suspects (pin diodes):
>>>> D1 and D5 on the KXV3A: o.k.
>>>> Each and every pin diode on the SUB IN board: o.k.
>>>> D5 on the Main RX board: o.k.
>>>>
>>>> This is a K3 #59xx with almost everything inside money can buy.
>>>>
>>>> My second K3 (serial #39xx) does not show this strange behavior.
>>>> Main RX and SUB RX show exactly the same values on ANT1/2 and AUX
>>>> IN. -33dBm is 59+40 on MAIN and SUB RX, no matter if Ant1, 2 or AUX IN.
>>>>
>>>> Any idea? I'm searching for weeks now and I'm close to give up.
>>>>
>>>> Udo, DK5YA
>>> ______________________________________________________________
>>> Elecraft mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>> Help: http://mailman.qth.net/mmfaq.htm
>>> Post: mailto:[hidden email]
>>>
>>> This list hosted by: http://www.qsl.net
>>> Please help support this email list: http://www.qsl.net/donate.html
>>> Message delivered to [hidden email]
>>
>>
>

Don Wilhelm

Re: K3: Main RX gone deaf

Udo,

If you check the block diagram of the K3 you should see the area where
the problem is located (page 76).

Does the main have the same response as the subRX if you use the RX ANT IN?
If so, there is a problem with either the T/R switch or the Low Pass
filter area.

If the main RX response is still not the same as the subRX when using
the RX ANT IN, then the problem is in the main receiver itself.

73,
Don W3FPR

On 4/30/2016 5:57 PM, Udo Langenohl - DK5YA wrote:

> Gents,
>
> I had another test session today with my K3 and here's what I've done
> and what happened:
>
> 1. I've checked all the test points recommended by Elecraft. No issue
> found, all stages are working, there's noise increasing on each test
> point at the Main RX.
>
> 2. Fired up my signal generator again and started on the Main RX with
> a signal on the following frequencies and with these results:
>

Vic Rosenthal

Re: K3: Main RX gone deaf

In reply to this post by Udo Langenohl - DK5YA

I would suspect one of the relays in the path from the antenna, through the RX ant switching circuitry. Then there are the diodes in the t/r switch.
If you have verified that the RX is working, it must have something to do with the path from the antenna.
Does it transmit OK? The lowpass filters are in the main RX path, I think.

Vic 4X6GP

> On 1 May 2016, at 12:57 AM, Udo Langenohl - DK5YA <[hidden email]> wrote:
>
> Gents,
>
> I had another test session today with my K3 and here's what I've done and what happened:
>
> 1. I've checked all the test points recommended by Elecraft. No issue found, all stages are working, there's noise increasing on each test point at the Main RX.
>
> 2. Fired up my signal generator again and started on the Main RX with a signal on the following frequencies and with these results:
>
> Filter settings: 2.7KHz
> Preamp off
> Att: no
> Signal strength: -63 dBm
> Mode: USB
>
> 28.130 = S6
> 21.130 = S6
> 18.130 = S4
> 14.130 = S2 (!!)
> 10.130 = S4
> 7.130 = S8 (!!)
> 3.513 = S6
>
> Same settings at the Sub RX (via AUX IN):
>
> 28.130 = S9+5
> 21.130 = S9+10
> 18.130 = S9+10
> 14.130 = S9+10
> 10.130 = S9+5
> 7.130 = S9+10
> 3.513 = S9+10
>
> You will see that there are dramatic differences at the Main RX from band to band and from S2 (14 MHz) up to S8 (7 MHz). And of course when comparing Main RX with Sub RX. Also tried different filter settings (AM, CW), no change.
>
> I have no idea what is happening here and what to do next.
>
> 73 Udo, DK5YA
>
>
>> Am 25.04.2016 um 22:02 schrieb Udo Langenohl - DK5YA:
>> Gentleman,
>>
>> thanks for all so many replies. Will try to check all ideas tomorrow,
>> XYL permitting ... ;-).
>>
>> 73 Udo, DK5YA
>>
>> P.S.: The issue occurs at the RX IN and TVTR IN ports of the KXV3A too.
>>
>>> Am 25.04.2016 um 17:57 schrieb Jerry:
>>> Reseat the internal coax jumpers in the surf signal path.
>>>
>>> Sent from my iPad
>>>
>>>> On Apr 25, 2016, at 11:52 AM, Graham g3tct <[hidden email]> wrote:
>>>>
>>>> Hi Udo
>>>> Before you start tearing the rig apart, two ideas:-
>>>>
>>>> -is there a big difference for weak signals of say S4?
>>>> -if not, it may just be the S meter calibration that needs attention.
>>>> -if so, preamp on for either? Att on for main?
>>>>
>>>> HTH
>>>> Graham
>>>>
>>>>> On 19:59, Udo Langenohl - DK5YA wrote:
>>>>> Gentleman,
>>>>>
>>>>> I'm struggling with a Main RX vs. Sub RX issue. My Main RX is rather
>>>>> deaf compared to the Sub RX. I see at least 23.5dB attenuation
>>>>> between Main RX and Sub RX when comparing highly stable signals from
>>>>> my signal generator (HP8664A). This is only for ANT1/2 vs. AUX-IN!
>>>>> Example:
>>>>> -33dBm on 28.500
>>>>> into AUX-IN (SUB RX): exactly 59 +40dB
>>>>> into ANT 1 (Main RX): 59 +15dB
>>>>> into ANT 2 (Main RX): 59 +15dB
>>>>>
>>>>> I've checked all the usual suspects (pin diodes):
>>>>> D1 and D5 on the KXV3A: o.k.
>>>>> Each and every pin diode on the SUB IN board: o.k.
>>>>> D5 on the Main RX board: o.k.
>>>>>
>>>>> This is a K3 #59xx with almost everything inside money can buy.
>>>>>
>>>>> My second K3 (serial #39xx) does not show this strange behavior.
>>>>> Main RX and SUB RX show exactly the same values on ANT1/2 and AUX
>>>>> IN. -33dBm is 59+40 on MAIN and SUB RX, no matter if Ant1, 2 or AUX IN.
>>>>>
>>>>> Any idea? I'm searching for weeks now and I'm close to give up.
>>>>>
>>>>> Udo, DK5YA
>>>> ______________________________________________________________
>>>> Elecraft mailing list
>>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>>> Help: http://mailman.qth.net/mmfaq.htm
>>>> Post: mailto:[hidden email]
>>>>
>>>> This list hosted by: http://www.qsl.net
>>>> Please help support this email list: http://www.qsl.net/donate.html
>>>> Message delivered to [hidden email]
>
> --
> ******************************************
> Webs by DK5YA: *
> http://www.mmmonvhf.de/ [editor]*
> http://www.vhfdx.de/ [owner] *
> http://www.palekastro.de/ [owner] *
> http://www.solweb.de/ [owner] *
> http://www.spessartwetter.de/ [owner] *
> ******************************************
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

Udo Langenohl - DK5YA

Re: K3: Main RX gone deaf

Vic,

TX works perfect, it's just a RX issue. The pin diodes are all o.k., my
guess: a relay has gone crazy in the switching circuitry. Or it's a low
pass filter issue. Will investigate in these parts now.

73 Udo, DK5YA

Am 01.05.2016 um 06:40 schrieb Vic Rosenthal:

> I would suspect one of the relays in the path from the antenna, through the RX ant switching circuitry. Then there are the diodes in the t/r switch.
> If you have verified that the RX is working, it must have something to do with the path from the antenna.
> Does it transmit OK? The lowpass filters are in the main RX path, I think.
>
> Vic 4X6GP
>
>> On 1 May 2016, at 12:57 AM, Udo Langenohl - DK5YA <[hidden email]> wrote:
>>
>> Gents,
>>
>> I had another test session today with my K3 and here's what I've done and what happened:
>>
>> 1. I've checked all the test points recommended by Elecraft. No issue found, all stages are working, there's noise increasing on each test point at the Main RX.
>>
>> 2. Fired up my signal generator again and started on the Main RX with a signal on the following frequencies and with these results:
>>
>> Filter settings: 2.7KHz
>> Preamp off
>> Att: no
>> Signal strength: -63 dBm
>> Mode: USB
>>
>> 28.130 = S6
>> 21.130 = S6
>> 18.130 = S4
>> 14.130 = S2 (!!)
>> 10.130 = S4
>> 7.130 = S8 (!!)
>> 3.513 = S6
>>
>> Same settings at the Sub RX (via AUX IN):
>>
>> 28.130 = S9+5
>> 21.130 = S9+10
>> 18.130 = S9+10
>> 14.130 = S9+10
>> 10.130 = S9+5
>> 7.130 = S9+10
>> 3.513 = S9+10
>>
>> You will see that there are dramatic differences at the Main RX from band to band and from S2 (14 MHz) up to S8 (7 MHz). And of course when comparing Main RX with Sub RX. Also tried different filter settings (AM, CW), no change.
>>
>> I have no idea what is happening here and what to do next.
>>
>> 73 Udo, DK5YA
>>
>>
>>> Am 25.04.2016 um 22:02 schrieb Udo Langenohl - DK5YA:
>>> Gentleman,
>>>
>>> thanks for all so many replies. Will try to check all ideas tomorrow,
>>> XYL permitting ... ;-).
>>>
>>> 73 Udo, DK5YA
>>>
>>> P.S.: The issue occurs at the RX IN and TVTR IN ports of the KXV3A too.
>>>
>>>> Am 25.04.2016 um 17:57 schrieb Jerry:
>>>> Reseat the internal coax jumpers in the surf signal path.
>>>>
>>>> Sent from my iPad
>>>>
>>>>> On Apr 25, 2016, at 11:52 AM, Graham g3tct <[hidden email]> wrote:
>>>>>
>>>>> Hi Udo
>>>>> Before you start tearing the rig apart, two ideas:-
>>>>>
>>>>> -is there a big difference for weak signals of say S4?
>>>>> -if not, it may just be the S meter calibration that needs attention.
>>>>> -if so, preamp on for either? Att on for main?
>>>>>
>>>>> HTH
>>>>> Graham
>>>>>
>>>>>> On 19:59, Udo Langenohl - DK5YA wrote:
>>>>>> Gentleman,
>>>>>>
>>>>>> I'm struggling with a Main RX vs. Sub RX issue. My Main RX is rather
>>>>>> deaf compared to the Sub RX. I see at least 23.5dB attenuation
>>>>>> between Main RX and Sub RX when comparing highly stable signals from
>>>>>> my signal generator (HP8664A). This is only for ANT1/2 vs. AUX-IN!
>>>>>> Example:
>>>>>> -33dBm on 28.500
>>>>>> into AUX-IN (SUB RX): exactly 59 +40dB
>>>>>> into ANT 1 (Main RX): 59 +15dB
>>>>>> into ANT 2 (Main RX): 59 +15dB
>>>>>>
>>>>>> I've checked all the usual suspects (pin diodes):
>>>>>> D1 and D5 on the KXV3A: o.k.
>>>>>> Each and every pin diode on the SUB IN board: o.k.
>>>>>> D5 on the Main RX board: o.k.
>>>>>>
>>>>>> This is a K3 #59xx with almost everything inside money can buy.
>>>>>>
>>>>>> My second K3 (serial #39xx) does not show this strange behavior.
>>>>>> Main RX and SUB RX show exactly the same values on ANT1/2 and AUX
>>>>>> IN. -33dBm is 59+40 on MAIN and SUB RX, no matter if Ant1, 2 or AUX IN.
>>>>>>
>>>>>> Any idea? I'm searching for weeks now and I'm close to give up.
>>>>>>
>>>>>> Udo, DK5YA
>>>>> ______________________________________________________________
>>>>> Elecraft mailing list
>>>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>>>> Help: http://mailman.qth.net/mmfaq.htm
>>>>> Post: mailto:[hidden email]
>>>>>
>>>>> This list hosted by: http://www.qsl.net
>>>>> Please help support this email list: http://www.qsl.net/donate.html
>>>>> Message delivered to [hidden email]
>>
>> --
>> ******************************************
>> Webs by DK5YA: *
>> http://www.mmmonvhf.de/ [editor]*
>> http://www.vhfdx.de/ [owner] *
>> http://www.palekastro.de/ [owner] *
>> http://www.solweb.de/ [owner] *
>> http://www.spessartwetter.de/ [owner] *
>> ******************************************
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to [hidden email]
>