Topics

External PTT connection

Bob Hoffmann, K4CQO
 

I am trying to connect a QRM noise canceler to the unit (using a QRM-180) and I am having trouble getting the PTT relay to switch the noise canceler out of the circuit.

I purchased a cable that is connected to the ACC connection (13 pin plug) with an RCA jack on the other end with a built in relay. However, this is what I am seeing: on VHF the relay is not operated; on HF the relay is operated. This is the case if I transmit or receive -- it does not change the relay setting.

It appears to be set to control using an external amp for HF instead of for VHF -- but I am confused why it does not change when I transmit. Is there a setting that I have to use -- or did I get the wrong cable (the cable is supposed to be good for the ic-7000), or maybe the incorrect way of connecting the ic-7000 to the noise canceler?

The noise canceler uses a ground connection to switch it from receive mode to out of the antenna path when transmitting.

Rich Seifert
 

On Sep 26, 2019, at 5:57 AM, Bob Hoffmann, K4CQO <rjhoffmann@...> wrote:

I am trying to connect a QRM noise canceler to the unit (using a QRM-180) and I am having trouble getting the PTT relay to switch the noise canceler out of the circuit.

I purchased a cable that is connected to the ACC connection (13 pin plug) with an RCA jack on the other end with a built in relay. However, this is what I am seeing: on VHF the relay is not operated; on HF the relay is operated. This is the case if I transmit or receive -- it does not change the relay setting.

It appears to be set to control using an external amp for HF instead of for VHF -- but I am confused why it does not change when I transmit. Is there a setting that I have to use -- or did I get the wrong cable (the cable is supposed to be good for the ic-7000), or maybe the incorrect way of connecting the ic-7000 to the noise canceler?

The noise canceler uses a ground connection to switch it from receive mode to out of the antenna path when transmitting.
If you look at page 12 of the IC-7000 manual, you will see that there are TWO pins for PTT:

—Pin 3 (HSEND) is normally used for PTT on HF/50 MHz. Pulling this pin low will enable transmit on HF/50 MHz. It will not enable transmit on VHF/UHF.

—Pin 7 (VSEND) is normally used for PTT on VHF/UHF. It works exactly the same as pin 3, but for 144/430 MHz only.

This arrangement actually makes sense. In most applications (particularly mobile), you will use a different antenna for HF/50 MHz than for UHF/VHF. Additionally, the output drivers in the IC-7000 are separate for HF/50 MHz and UHF/VHF.

Now, you can change this behavior in the “Set” menu. What is shown above is the default. Look at page 131 of the manual, and you will see that, under the “Set” menu, you can change the parameter “VSEND Select” to “Off.” In this configuration the HSEND pin on the ACC jack will enable transmit (PTT) on ALL bands. This may be what you want.

Rich KE1B

Bob Hoffmann, K4CQO
 

Thanks for responding Rich.

However, what I am seeing is -- if on 2m & 70cm receive, the relay -- presumable from having voltage applied -- shows not connected. This is whether I am transmitting or not.

For any HF setting (including 6m), it shows that the relay is connected -- presumable by the voltage disconnected from the relay. Again this is whether I am transmitting or not. So the relay is on / off depending on what band the ic-7000 is set to.

Assuming that the hsend is connected to the relay -- that would mean that hsend is grounded whenever an HF band is selected, and not grounded when 2m or 70cm are selected. I was wandering if that is an operation on a different pin than 3 -- meaning that i have the wrong cable, or if there is something that is set in the ic-7000 that does that. 

It looks like there is no such setting -- only the scope of the vsend / hsend. So, can it be that I have the wrong wired cable -- is there a different pin that does that?

Rich Seifert
 



On Sep 26, 2019, at 11:47 AM, Bob Hoffmann, K4CQO <rjhoffmann@...> wrote:

Thanks for responding Rich.

However, what I am seeing is -- if on 2m & 70cm receive, the relay -- presumable from having voltage applied -- shows not connected. This is whether I am transmitting or not.

For any HF setting (including 6m), it shows that the relay is connected -- presumable by the voltage disconnected from the relay. Again this is whether I am transmitting or not. So the relay is on / off depending on what band the ic-7000 is set to.

Assuming that the hsend is connected to the relay -- that would mean that hsend is grounded whenever an HF band is selected, and not grounded when 2m or 70cm are selected. I was wandering if that is an operation on a different pin than 3 -- meaning that i have the wrong cable, or if there is something that is set in the ic-7000 that does that. 

It looks like there is no such setting -- only the scope of the vsend / hsend. So, can it be that I have the wrong wired cable -- is there a different pin that does that?
_._,_._,_

It sounds like what you want is the INVERSE of the HSEND/VSEND function. Those pins are used by an external device (e.g., a computer interface) to enable transmit on the IC-7000, either HF or VHF/UHF. From what you are saying, you want a signal that goes high (to energize a relay) when the radio is transmitting, e.g., when the manual PTT is pressed or a CW signal enables break-in. I don’t think such a signal is available (at least not easily).

Rich KE1B


Bob Hoffmann, K4CQO
 

Finally got it to work!

I saw in the manual that there was a 16 pin connector that was provided with the ic-7000 and wanted to look to see if I could use it to replace the one that I had in case the wrong pin was found to be used.

Well, the connector had a cable and an RCA plug on the end. So, I decided to try it. Plugged it into the ic-7000 and the RCA plug into the QRM-180 noise canceler. When I turned the units on, I could switch the band and the relay did not change – still in the receive mode. Then I keyed the transmit, and the QRM-180 switched to transmit mode and then back again to receive mode when the ic-7000 was back to receive mode. Exactly like it should work.

I noticed when looking at the manual that there was a user change to power pin 5 of the connector. I think that what was done and the cable (the one that I purchased from eBay that even has “7k” written on the connector) looks at pin 5 instead of pin 3. So the cable I got was an incorrect cable.

All is good and it is working to switch the QRM-180 to a bypass mode when the ic-7000 is transmitting. Now I just need to get the receive antenna connected and I can see how it works.

Thanks everybody for responding.

 

 

 

73 – K4CQO

Bob Hoffmann

 

 

From: ic7000@groups.io <ic7000@groups.io> On Behalf Of Rich Seifert
Sent: Thursday, September 26, 2019 3:45 PM
To: ic7000@groups.io
Subject: Re: [ic7000] External PTT connection

 

 



On Sep 26, 2019, at 11:47 AM, Bob Hoffmann, K4CQO <rjhoffmann@...> wrote:

 

Thanks for responding Rich.

However, what I am seeing is -- if on 2m & 70cm receive, the relay -- presumable from having voltage applied -- shows not connected. This is whether I am transmitting or not.

For any HF setting (including 6m), it shows that the relay is connected -- presumable by the voltage disconnected from the relay. Again this is whether I am transmitting or not. So the relay is on / off depending on what band the ic-7000 is set to.

Assuming that the hsend is connected to the relay -- that would mean that hsend is grounded whenever an HF band is selected, and not grounded when 2m or 70cm are selected. I was wandering if that is an operation on a different pin than 3 -- meaning that i have the wrong cable, or if there is something that is set in the ic-7000 that does that. 

It looks like there is no such setting -- only the scope of the vsend / hsend. So, can it be that I have the wrong wired cable -- is there a different pin that does that?

Joe Krout
 

Bob

I believe your issue is that Hsend and Vsend are on different pins on the 13 pin connector.  Hsend is on pin 3, Vsend is on pin 7.  They are two different transistor FET? Switches.

Makes sense, as they are used for amplifier switching, and there are 2 different PA outputs.

73
Joe
KR0UT 

On Thu, Sep 26, 2019, 7:57 AM Bob Hoffmann, K4CQO <rjhoffmann@...> wrote:
I am trying to connect a QRM noise canceler to the unit (using a QRM-180) and I am having trouble getting the PTT relay to switch the noise canceler out of the circuit.

I purchased a cable that is connected to the ACC connection (13 pin plug) with an RCA jack on the other end with a built in relay. However, this is what I am seeing: on VHF the relay is not operated; on HF the relay is operated. This is the case if I transmit or receive -- it does not change the relay setting.

It appears to be set to control using an external amp for HF instead of for VHF -- but I am confused why it does not change when I transmit. Is there a setting that I have to use -- or did I get the wrong cable (the cable is supposed to be good for the ic-7000), or maybe the incorrect way of connecting the ic-7000 to the noise canceler?

The noise canceler uses a ground connection to switch it from receive mode to out of the antenna path when transmitting.

tunert51@...
 

Hello , I just thought I would add a simular question regarding PTT. If I  were add a different mic and preamp to pins 11 and 2 on the ACC Jack,  can I make a PTT for use through one of the modular jacks? Any info would be much appreciated:) 


73 de VA3GRV. Vince ee