Let me restate this. The diode needs to "point" at the K3 in order for
>
>> Anodes towards K3/KPA500 signal junction. Just one diode needed per
>> BCD signal.
>
> No, that will not work since anode to K3/KPA500 will not allow the K3
> to pull the RCS-12 inputs low. Since I don't have a schematic for the
> RCS-12 (none published as far as I can fine), my assumption is that
> the RC-12 has pull-ups on its BCD input.
>
> I suppose Dave could measure the voltage on pins 1,2,8 & 9 of the
> RCS-12 "Radio Input" jack. That would give some hint as to the
> circuit design. (I don't know why I'm trying to debug MFJ stuff -
> just get a real band decoder <G>).
>
> 73,
>
> ... Joe, W4TV
>
>
> On 6/15/2011 6:18 PM, Jack Brindle wrote:
>> Nope. That won't work. The BCD outputs are open drain/collector, so
>> connecting them in this way will actually do nothing.
>> Anodes towards K3/KPA500 signal junction. Just one diode needed per
>> BCD
>> signal.
>>
>> Jack Brindle, W6FB
>>
>> On Jun 15, 2011, at 3:06 PM, Joe Subich, W4TV wrote:
>>
>>>
>>>> What kind of isolation diodes would you suggest?
>>>
>>> Any switching diode (1N4148, etc.) would be fine.
>>>
>>>> Any how should they be connected?
>>>
>>> As any set to isolation diodes ... two diodes per data line
>>> (A,B,C,D)
>>> cathodes to the K3, anodes to the RCS-12 and KPA-500.
>>>
>>> 73,
>>>
>>> ... Joe, W4TV
>>>
>>>
>>> On 6/15/2011 12:11 AM, Dave Perry wrote:
>>>> Joe,
>>>>
>>>> Yes, I am using the four pins corresponding to Band 0 through
>>>> Band 3
>>>> plus the pin for ground. The RCS-12 works fine connected directly
>>>> to the
>>>> ACC port on the K3. It also works fine when the KPA500 is
>>>> connected via
>>>> the Y cable. It is just that the KPA500 is not switching bands when
>>>> connected with the RCS-12. So your suspicion may be correct. What
>>>> kind
>>>> of isolation diodes would you suggest? Any how should they be
>>>> connected?
>>>>
>>>> Thank you.
>>>>
>>>> Dave, N4QS
>>>>
>>>> ----- Original Message ----- From: "Joe Subich, W4TV" <
[hidden email]
>>>> >
>>>> To: <
[hidden email]>
>>>> Sent: Tuesday, June 14, 2011 10:43 PM
>>>> Subject: Re: [Elecraft] KPA500 question
>>>>
>>>>
>>>>>
>>>>> You might try isolation diodes between the antenna switch and/or
>>>>> KPA and the K3. If the KPA is not band switching with the RCS-12
>>>>> connected, I would suspect the RCS-12 is loading the band data
>>>>> lines.
>>>>>
>>>>> How are you connecting the RCS-12? Are you using the "Yaesu BCD"
>>>>> connections?
>>>>>
>>>>> 73,
>>>>>
>>>>> ... Joe, W4TV
>>>>>
>>>>>
>>>>>
>>>>> On 6/14/2011 11:24 PM, Dave Perry wrote:
>>>>>> Gary,
>>>>>>
>>>>>> Good suggestion. I removed the cable going to the antenna
>>>>>> switch and
>>>>>> now the K3 and KPA500 appear to talk to one another when changing
>>>>>> bands. Pushing a band button on the amp changes the amp and the
>>>>>> K3 to
>>>>>> the new band. I still cannot get the two power levels to work.
>>>>>> I also
>>>>>> need to figure out how to get the band switch working with the Y
>>>>>> cable.
>>>>>>
>>>>>> Dave, N4QS
>>>>>> ----- Original Message -----
>>>>>> From: Gary Gregory
>>>>>> To: Dave Perry
>>>>>> Sent: Tuesday, June 14, 2011 10:12 PM
>>>>>> Subject: Re: [Elecraft] KPA500 question
>>>>>>
>>>>>>
>>>>>> What bothers me is the amp was not switching bands you
>>>>>> said?...If the
>>>>>> OPER switch is set then the aux cable should allow you to switch
>>>>>> bands either way and the amp should indeed switch bands and
>>>>>> indicate
>>>>>> that on the LCD.
>>>>>>
>>>>>>
>>>>>> Unfortunately, my FT unit has the original I/O board so I can't
>>>>>> verify this for you...sorry
>>>>>>
>>>>>>
>>>>>> remove the antenna switch and try see if that makes any
>>>>>> difference.
>>>>>>
>>>>>>
>>>>>> Gary
>>>>>>
>>>>>>
>>>>>> On 15 June 2011 13:02, Dave Perry<
[hidden email]> wrote:
>>>>>>
>>>>>> Gary,
>>>>>>
>>>>>> No, I did not remove any pins on the cable. This is the one
>>>>>> supplied
>>>>>> by Elecraft and I figured that it would be good to go. I just
>>>>>> checked
>>>>>> the cable and five pins have been removed. I just removed the Aux
>>>>>> Cable from the back of the KPA500 and now the band buttons work
>>>>>> on
>>>>>> the amp. So it does appear that the Aux Cable is the culprit.
>>>>>>
>>>>>> Dave
>>>>>> ----- Original Message -----
>>>>>> From: Gary Gregory
>>>>>> To: Dave Perry
>>>>>> Sent: Tuesday, June 14, 2011 9:49 PM
>>>>>> Subject: Re: [Elecraft] KPA500 question
>>>>>>
>>>>>>
>>>>>> Do you have PIN 10 removed on the KPA-500 end of the Y cable?
>>>>>>
>>>>>>
>>>>>> Gary
>>>>>>
>>>>>>
>>>>>> On 15 June 2011 12:33, Dave Perry<
[hidden email]> wrote:
>>>>>>
>>>>>> My KPA500 sn 70 arrived tonight (factory assembled). It took
>>>>>> just a
>>>>>> few minutes to hook up and get it on the air. I am using the Y
>>>>>> cable
>>>>>> on the ACC port to split off two cables from the K3 ACC port --
>>>>>> one
>>>>>> goes to a new RCS-12 Automatic Antenna Switch and the other
>>>>>> goes to
>>>>>> the KPA500.
>>>>>>
>>>>>> I have AUX BUS on the KPA500 menu turned on and Band Change set
>>>>>> to
>>>>>> normal. If I press a band button on the amp, the K3 changes
>>>>>> bands and
>>>>>> so does the new antenna switch -- pretty neat. But the band
>>>>>> display
>>>>>> on the KPA does not change. I have to hit the key and transmit
>>>>>> to get
>>>>>> the band to change on the KPA500. This does not seem correct. It
>>>>>> would seem that pressing any on the band buttons on the amp
>>>>>> should
>>>>>> change the band on the amp and the frequency display as well.
>>>>>>
>>>>>> Likewise if I change bands on the K3 or via my logging
>>>>>> software, the
>>>>>> K3 and antenna switch change bands, but the KPA500 does not. I
>>>>>> have
>>>>>> to tap the paddle and transmit to get the KPA500 to change to the
>>>>>> correct band. I am wondering if there is a problem with the Aux
>>>>>> Cable. Any other suggestions?
>>>>>>
>>>>>> I am up to date on firmware for both the K3 and KPA500.
>>>>>>
>>>>>> The amp runs very quiet and is silky smooth in full QSK mode. I
>>>>>> just
>>>>>> need to get the band changing issue resolved. Any help would be
>>>>>> appreciated.
>>>>>>
>>>>>> Thank you.
>>>>>>
>>>>>> Dave, N4QS
>>>>>> ______________________________________________________________
>>>>>> 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>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>>
>>>>>> VK4FD - Motorhome Mobile
>>>>>> Elecraft Equipment
>>>>>> K3 #679, KPA-500 #018
>>>>>> Living the dream!!!
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>>
>>>>>> VK4FD - Motorhome Mobile
>>>>>> Elecraft Equipment
>>>>>> K3 #679, KPA-500 #018
>>>>>> Living the dream!!!
>>>>>>
>>>>>> ______________________________________________________________
>>>>>> 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:
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http://www.qsl.net/donate.html>>>>>>
>>>>> ______________________________________________________________
>>>>> 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
>>>>
>>>>
>>> ______________________________________________________________
>>> 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:
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http://www.qsl.net/donate.html>>
>>
> ______________________________________________________________
> Elecraft mailing list
> Home:
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http://mailman.qth.net/mmfaq.htm> Post: mailto:
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>
> This list hosted by:
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