Anan 10e, k19 mod yes or no?

cleanrf
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Anan 10e, k19 mod yes or no?

Postby cleanrf » Mon Aug 20, 2018 9:18 pm

I am getting conflicting advice regarding modifying the anan 10e to use an external amp with puresignal. I have read modify k19 by removing the ground and route to sma on back of the radio and then I read that this will allow to much cross talk. What is the correct way to go about this? I am using the xtronics sampler with a 1200 watt amplifier. I have another recent post that hasn't received any replies about the way I am trying to do this now.

Thanks in advance
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w-u-2-o
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Re: Anan 10e, k19 mod yes or no?

Postby w-u-2-o » Tue Aug 21, 2018 1:40 am

I don't think very many people have modified their 10 or 10E for PureSignal. You may just have to try it and see. Modifying K19 certainly looks like a very straightforward way of solving the problem, though. I would not think there would be excessive crosstalk in a 10W radio.

73,

Scott
cleanrf
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Re: Anan 10e, k19 mod yes or no?

Postby cleanrf » Tue Aug 21, 2018 1:55 am

I tend to agree regarding the cross talk. I just seem to remember Stu advising against the K19 to SMA mod. I am going to give it a shot.
AB2EZ
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Re: Anan 10e, k19 mod yes or no?

Postby AB2EZ » Tue Aug 21, 2018 11:23 pm

I suggest that you read my post on the Apache Labs Yahoo Group site: post #21345 dated December 8 2015.

This post explains how to provide Pure Signal input from an external amplifier to an ANAN10E without making any internal mods to the transceiver.

This approach has been working fine for me for over 4 years with my ANAN10E and my Elecraft KXPA100 amplifier

Stu
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w-u-2-o
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Re: Anan 10e, k19 mod yes or no?

Postby w-u-2-o » Tue Aug 21, 2018 11:24 pm

@AB2EZ

Stu,

Why don't you cross post it here so it is not so hard to find?

73,

Scott
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Re: Anan 10e, k19 mod yes or no?

Postby AB2EZ » Wed Aug 22, 2018 12:18 am

Below is the text of the description of the approach I use.

The block diagram is here:

https://groups.yahoo.com/neo/groups/apa ... 1997804010

Image

I have an ANAN-10E, which I use in conjunction with a 100W Elecraft KXPA100 solid state linear amplifier.

I have posted information on the Yahoo Groups Apache Labs web site regarding how I use Pure Signal without having to make any modifications to the ANAN-10E.

When transmitting, the "RX" SMA connector on the back of the ANAN-10E provides an input to the ANAN-10E's receiver... even though the ANAN-10E's schematic shows that there is a relay (k19) that places a short to ground across the input of the ANAN-10E's receiver... on transmit. The reason is that, inside the ANAN-10E, there is a short length of 50 ohm coaxial mini cable between the input of the ANAN-10E's receiver and relay k19. The impedance... looking into the receiver end of this coaxial mini cable... is not 0 ohms when k19 is in the transmit position. It is actually (using a Smith chart to calculate the impedance of a shorted length of coaxial cable) about j5 ohms on 40 meters, j2.5 ohms on 75 meters, j10 ohms on 20 meters, etc.

I place an external 2 watt, non-inductive, 50-ohm resistor, located adjacent to the ANAN-10E's RX SMA connector, in series with the RX SMA input connector.

The result is, for example, on 40 meters: the impedance... looking into the added resistor that is connected in series with the SMA RX port... is very close to 50 ohms (resistive). I.e. 50 ohms + j5 ohms is approximately 50 ohms. In addition, the combination of the added 50 ohms of series resistance and the impedance looking directly into RX the SMA port (i.e. j5 ohms) forms a 20dB voltage divider [i.e. j5/(50+j5)] feeding into the receiver of the ANAN-10E on transmit.

In the case of my setup, I drive the input side of the added 50-ohm series resistor (located adjacent the ANAN10's RX SMA connector), using 50-ohm coaxial cable... with a 10:1 current transformer that is sampling the output of my 100W amplifier. The secondary of the current transformer has a fixed, 5W, 150 ohm, non-inductive resistor directly across it (for safety). Therefore, the parallel combination of that 150 ohm resistive load, and the 50 ohm resistive load looking into the coaxial cable that feeds the RX SMA input of the ANAN-10E, produces a total load across the secondary of the current transformer of 37.5 ohms. The voltage reduction between the output of the amplifier and the output of the current transformer is, therefore, (1/10) x 37.5 ohms/50 ohms = .075 = (approximately) 22.5dB.

The net voltage attenuation between the output of the amplifier and the input of the ANAN's receiver is (approximately) 22.5dB + 20dB = 42.5dB. That works fine with my 100W amplifier, for providing a proper feedback signal for Pure Signal. I.e. with this level of external feedback, Pure Signal sets the ANAN's internal adjustable receiver input attenuator to 17dB. The total voltage attenuation between the 100V peak RF output voltage of the amplifier, and the input to the ANAN receiver's RF preamplifier (including the attenuation of the ANAN's internal adjustable receiver input attenuator) is 42.5dB + 17dB = ~60dB. Therefore, the Pure Signal input voltage, to the receiver's RF preamplifier, has amplitude: 100mV peak. The ANAN receiver's RF preamplifier has a gain of 20dB... so the Pure Signal input voltage to the A/D converter = 10 X 100mV peak = 1V peak.

If you have a 1000 watt output amplifier chain, then you need an additional 10dB of attenuation in the feedback path. You might implement this by using 30 turns on the current transformer’s secondary, instead of 10 turns.

Also, if you are going to operate the transceiver + amplifier at frequencies above 14.3MHz (i.e. on 17m, 15, 12m, 10, and/or 6m), you will need to increase the attenuation between the amplifier’s output and the ANAN-10E’s RX SMA input… by adding an additional 10dB attenuator between the output from the current transformer’s secondary winding (which still has a 150 ohm resistor directly across the secondary winding, inside the box) and the 50 ohm resistor that has been added in series with the ANAN-10E’s RX SMA input. This can be accomplished with a symmetrical 50-ohm impedance, 10dB, pi-shaped resistive attenuator. [I.e. a 100-ohm non-inductive resistor for each leg of the pi, plus a 68-ohm non-inductive resistor for the top of the pi]

Stu
Last edited by AB2EZ on Sat Aug 25, 2018 2:53 pm, edited 8 times in total.
cleanrf
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Re: Anan 10e, k19 mod yes or no?

Postby cleanrf » Wed Aug 22, 2018 5:15 am

This is the conflicting information I was referring to. I would like to find a way to use the xtronics directional coupler. How is k19 different than the way this scenario is accomplished on the ANAN rigs that run puresignal with external amplifier? Like the later ANAN 100, 100D, and 200D? I also see the TAPR TR-Plus for sale that requires to remove the jumper between J3 and J29, this is the first mods I tried but I built my own T/R relay. This was surely allowing puresignal to work just not sure how well. I use a 1200 watt amplifier and would like to find a resolution that works best.
cleanrf
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Re: Anan 10e, k19 mod yes or no?

Postby cleanrf » Sat Aug 25, 2018 5:10 am

So is the xtronics sampler useless for the anan 10 and 10E?
What about this https://www.tapr.org/kits_trplus.html ? You guys that seem to know all the bells and whistles about these rigs post up your thoughts.
Thanks
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Re: Anan 10e, k19 mod yes or no?

Postby w-u-2-o » Sat Aug 25, 2018 1:29 pm

cleanrf wrote:So is the xtronics sampler useless for the anan 10 and 10E?
Not at all! In fact it is probably the best high power, HF coupler available (it's a true coupler, not a "sampler"). It has a nearly ruler flat coupling gain from 160M to 10M, and will work for 6M. And you need a coupler of some sort no matter what (unless you have one of those amp's with a built-in coupler).

What about this https://www.tapr.org/kits_trplus.html ? You guys that seem to know all the bells and whistles about these rigs post up your thoughts.
I can only speak from hearsay, as I do not have an ANAN-10 or 10E, but that kit has a very good reputation. I'd recommend that you place it into a metal enclosure so that it is well shielded and provision some RCA connectors for PTT pass-through and a coaxial ("barrel") type power connector. I'm partial to Hammond extruded enclosures.

It's three different ways of accomplishing the same thing. Personally I'd go with the TAPR approach or the K19 method because you already own the excellent Xtronic coupler, it is much easier to debug switching than the careful impedance matching that Stu's approach utilizes, and it will work on all bands and frequencies, no fuss, no muss.

73,

Scott

P.S. Stu--obviously I can't be posting/hosting photos for everyone on the forum, but since you already had the image hosted on the Yahoo site I took the liberty of editing in an appropriate link into your post. You might take a look at it (edit your post) so you can see how to do it in the future.
cleanrf
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Re: Anan 10e, k19 mod yes or no?

Postby cleanrf » Mon Aug 27, 2018 6:05 pm

Thanks for the reply Scott.
I carefully removed K19 from the board and reinstalled with the legs originally grounded now pointing up and routed to a small piece of coax that led to a SMA female on the back of the radio. I drilled a hole in the back panel. After reassembling the radio it would not power up. That issue turned out to be a broken wire at the molex connector on the power wire between the 2 boards, repaired now radio fires up fine but I had no receive and puresignal flashing red. I opted to just reinstall relay and put radio back to stock when I realize the issue was the jumper between J3 and J29. One of the small Mini PCI UFL connectors on the jumper was damaged and not making contact. I did not have any of these but I did have a few Mini PCI UFL to female SMA pigtails that were about 3" long so I used 2 of these and drill another hole in the back of the radio. I have various lengths of male sma to male sma jumpers and use a 5" one to connect j3 and j29 together on the back of the radio. The radio is back working but I have not done anything else since then. I still like the idea of lifting the grounded side of K19 but will not attempt until I have a spare relay or 2 on hand. I am on the fence about the K19 vs the external relay route. I will report back what I end up doing.

Steve
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w-u-2-o
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Re: Anan 10e, k19 mod yes or no?

Postby w-u-2-o » Mon Aug 27, 2018 6:20 pm

OK, Steve. We will all be very interested in how it turns out!

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