Icom IC-9700 users topic

[VK4GHZ]

Has anyone looked for the TCXO in the 9700? I wonder if it's possible to put a bit of foam or other insulating material over/around it to minimise the influence of the fan.

Lou, apparently the TCXO module already has foam around it.

The usual Facebook stuff, not a huge amount of detail, along with photos that leave more questions than answers.

In this image, the TSCO [sic] is the small enclosure:

And that was the end of it.


Perhaps some foam material inside the TSCO (!) enclosure would help increase the thermal mass, and help slow down the temperature transitions.
Anyone game to spray some expanding foam gunk in there?

Edit: Process of elimination suggests the TCXO is smaller of the two shielded cans.

[VK7HH]

Rex is in the current stages of drafting up a full and comprehensive review on the 9700.

We had some discussion the other day whilst making the YouTube video about the possibility of GPS locking. If the TCXO is easy to access, then perhaps this is an option.
Interesting that it already has foam around it. If it does, then imagine without. As a comparison my FT-991 drifts a maximum of 3Hz at 432MHz regardless of fan speed.

We agreed in general that Icom made a poor decision with the 10 MHz reference input implementation on the 9700 which has been featured on the IC-7610 correctly. It's 2019, it should be a standard feature.

[VK3QI]

Hayden,

I sent a message to Rex after the post from VK1XX about the 49.152 TCXO, but I am not sure if he saw it. My comments related to the implementation of the SDR up to 450MHz, which, for good RMDR requires clear processing power up to 900 MHz.

Icom are the first of the "ham" manufacturers to implement direct SDR at such a high frequency. Board layout becomes super critical to ensure that harmonics etc. are kept at bay. That probably brings in the reason why they chose an off the shelf 49.152 Mhz TCXO that would fit easily on the board.

The problem as I see it, is how does one successfully introduce a GPS locked 49.152 frequency into the rig without compromising the performance of the rig at 144 and 432MHz.

Remember that the IC7610 and other rigs which use a true 10MHz external reference, only go to 60 MHz.

Perhaps it comes down to a decision - does one go for accurate non-zero frequency drift and compromise the performance of the rig's other specifications or does one maintain the rig's other specifications and accept the frequency drift and have a pushbutton frequency accuracy function that can be pressed every few minutes?

No doubt the Icom engineers who designed the IC9700, would have investigated this issue, based on their experience with the IC7610.

********************
Interestingly, the IC9700.io group members are just now starting to make posts about the PTT issue controlling several external amplifiers. Something that has been an issue with all previous VHF/UHF rigs that Icom has produced.

Cheers

Peter VK3QI

[VK7HH]

The problem as I see it, is how does one successfully introduce a GPS locked 49.152 frequency into the rig without compromising the performance of the rig at 144 and 432MHz

All I can say is, where is David VK3HZ when you need him

[VK3QI]

Hayden,

I haven't spoken with David and Graham 3XDK for quite some time.

But the problem of producing a GPS locked 49.152MHz signal is not really the issue. VHF Design, Leo Bodnar and others can all produce such a board --> the problem is getting it into the rig successfully, without compromising the rest of the rig.

Peter

[VK7HH]

the problem is getting it into the rig successfully, without compromising the rest of the rig

Exactly. David and Co had a good way of working that all out with their previous XRef iterations. A Leo Bodnar GPS unit has been on my want list for a while. Perhaps I should purchase one shortly for the shack and potential experimenting. Even more pressing is getting such a solution into the rig if you can't access the TCXO, which may possible be the case with this radio, or so I've been told.

[VK4GHZ]

The external reference does NOT appear to feed the FPGA directly.
So re-configuring the FPGA with a firmware change is unlikely.

If it were that easy, I'm sure Icom would have implemented that.

The Ext Ref input is near an LTC2156 dual-channel ADC.

A 2-channel simultaneous sampling 250Msps/210Msps/170Msps 14-bit A/D converters designed for digitizing high frequency, wide dynamic range signals.
They are perfect for demanding communications applications with AC performance that includes 70dB SNR and 90dB spurious free dynamic range (SFDR).
The 1.25GHz input bandwidth allows the ADC to undersample high frequencies with good performance.
The latency is only six clock cycles.

https://www.analog.com/en/products/ltc2 ... t-overview

The two channels are simultaneously sampled by a shared encode circuit.

The ENC Clock inputs can be seen coming from top right of the image, which I believe is from the FPGA which resides within the large shielded area.
(Think of these parallel PCB tracks as balanced lines.)

LTC2156/57 device pinout;

The ENC input controls the sampling rate of the ADC inputs.

It's not clear where the Ext 10 MHz Ref Input comes into this, but why place the Ext Ref input near this ADC, and not the FPGA?

General overview:

[VK3QI]

Good question Adam.

Hopefully the Icom engineers will bring out a series of technical reports (http://www.icom.co.jp/world/products/am ... l2_Eng.pdf) like they did with the IC7610 explaining why they didn't implement 10MHz locking and explaining why they needed to use such a high reference frequency.

Cheers

Peter

[VK7HH]

Complete review and findings by Rex VK7MO -

https://drive.google.com/open?id=1fI5zZ ... ERRNJ3KfwU

[VK3ZAZ]

Someone on the 9700 facebook pages speaks of turning fan onto continuous running at low speed which has stabilised the drift somewhat 1-4 hz.
You bridge a 6 volt zener across the fan control transistor or some such trick.

[VK3ZAZ]

Finally after stuffing around got wsjt-x rc5 time limited it has 9700 in drop down and have cat control.
OER and I are going to try FT8 FT4 and JT65 on 144.313 this morning.
I can already tell you rig has the classic banana tail.
Time will tell if it screws up the jt65 and jt9 decodes.
Rex sent me a screen shot of when his aircon kicks in.
Inam amazed icom never stuck this innan oven and che ked out is characteristics between +55c and ambient, wonder how it will work in the shack or caravan on field day on a hot summers day watching for ZL wspr signals?
what does rig do in hot direct sunlight?
anyone?

[VK3QI]

Steve,

The simple answer amongst all the various suggestions being put forward, is that Icom should have made possible a 10Mhz locking option, as they have done with the 7610 model.

There may be technical difficulties in doing so, given the constraints on using SDR up to 440 MHz, but we need to wait on Icom to give their justification for not implementing it.

GPS locking has been available on various transverters since 2006 and on rigs like the 910, 9100 and ts2000 since 2012.

If GPS locking was available, then the problem is solved - reference the dead straight line in Rex's video when he put up a plot using a GPS locked 9100.

For years In the field at VK3ER/p we have been using GPS locking under temperature extremes from 0 to 50+ C with no discernible drift whatsoever. We can go from 1.2 Ghz to 24 Ghz with absolute certainty within 1 Hz. (Actually 47GHz now, but not tested under such extreme temperature differences yet).

The latest Icom.io posts talk about changing to an ultra-high stability OCXO on 49.152 MHz - most likely at a cost approaching the cost of the entire rig - totally impractical!

Cheers

Peter VK3QI

[VK3QI]

Good morning,

Having had a chance now to study the IC9700 service manual, it MAY give a clue as to why the IC 9700 is not 10 Mhz locked.

The master oscillator is 49.152MHz.

In order to produce RECEPTION on the 1240 - 1300 MHz band, the IF frequencies of 311 Mhz to 371 MHz are produced by mixing a conventional PLL operating on 929 MHz, phase locked by a 196.608 MHz signal, which is produced by 4 times the master frequency of 49.152MHz.

The 929Mhz signal is heavily filtered by high and low bandpass filters.

****************

On the other hand, in order to produce TRANSMISSION on the 1240 - 1300 MHz band, the IF frequencies of 311 Mhz to 371 MHz are mixed using a conventional PLL operating on 1605.632 MHz, phase locked by a 196.608 MHz signal, which is produced by 4 times the master frequency of 49.152MHz.

The 1605.632 Mhz signal is heavily filtered by high and low bandpass filters.

***************

To produce the 196.608 MHz signal that phase locks the PLL to either 929 Mhz or 1605.632 Mhz, the master oscillator is doubled to 98.304, amplified, then through a BPF at 98.304, then doubled to 196.608, amplified, then through a BPF at 196.608 and finally split into RX and TX reference frequencies for the PLL operating on either 929MHz or 1605.632 MHz.

***************
The question that needs to be asked, is what happens to the 10Mhz reference signal if it is being used to lock the 49.152MHz signal which is then doubled and doubled again all in the space of a few centimetres on a circuit board with a minimal amount of shielding and the effect it would have on the PLL being locked at 929Mhz or 1605.632 Mhz?

Remember that the rig has to meet quite rigid spurious emission standards in order to be approved for sale in the USA.

No doubt, as time goes on, we should hear a justification from Icom as to why it was not 10MHz locked.


Cheers

Peter VK3QI

[VK3BQ]

haven't posted for a long time, but found the service manual and passed it onto peter for the above..

its here if anyone else would like a copy its here (11mb)

https://www.dropbox.com/s/r9jq6up0170n1 ... 0.pdf?dl=0

seems icons sponsorship of this drift car was appropriate!

*i cancelled my order, having an ic9100 with a 3hz lock

[VK7HH]

seems icons sponsorship of this drift car was appropriate!

[VK3AP]

haven't posted for a long time, but found the service manual and passed it onto peter for the above..

its here if anyone else would like a copy its here (11mb)

https://www.dropbox.com/s/r9jq6up0170n1 ... 0.pdf?dl=0

seems icons sponsorship of this drift car was appropriate!

*i cancelled my order, having an ic9100 with a 3hz lock

big_1543580680_image.jpg

Thanks for the link Andrew.

[VK3ZAZ]

One month in
50/50 accceptance polls being conducted on faceache!
Then the molest and modify factor kicks in.
World wide communicators but lost in translation are the JA reactions
The fact no one seems to have tested this radio in the year it floated around.
Now everyone hanging it on the design and wants to start hacking into it.
Said before price will be below 2k in a year
there will be units for sale molested and modified no longer covered by warranty
all due to hams who think they can better design radios.
50 years in bc here rule being never modify.
dont care what the justification is.
bolt on addins maybe acceptable.
but that solder in zener to fire up the fan is a gross band aid job.
hopefully the radio sent back to Icom will produce a factory approved fix.
otherwise we will be laughing stock in JA.
And trust me. JA companies take a LOT of convincing that they made a design mistake as in the V1600 KHD dtv water cooled pas which stressed fractured all the silver solder.
Most now out of service in less than 15 years.
2cents.

[VK3BA]

G'day Steve,

I accept your comments and perspective. I've been keeping a close interest in what Rex and Glen (and others) have found and what's in development. Great news for the Whisperers, FT8'ers, etc. But I'll take a difference tact and is a personal view...

Look what the IC-9700 is doing to the market and band utilisation. This rig is forcing the adjustment of the second-hand market for rigs such as the IC-910, TS-2000X, etc. Although not as much like what the IC-7300 has done to the lower end of the second-hand HF market. Some more of these 910's & 2000's are coming on the market at a price point that is within the reach of more people than before, resulting in more utilisation of the upper bands. Want evidence? Sorry, I prefer gut feeling. A classic example of this is a handy station in SW Vic now has my old 910H (inc 23cm). I've retained my 9100 for non-SSB purposes.

The 9700 has re-sparked my interest on 2/70/23 SSB after a 6 year hiatus and has triggered a fair amount of construction & cabling work here in recent times in order to play on these three bands on SSB.

For me, my IC-9700 is working to Icom's specs. I'm another regularly satisfied customer of Icom. I love this rig and I'll probably depart my shack before this rig does. I love how it operates, how well it operates, it's user interface, usual Icom ergonomics & build quality. I'm impressed with the receiver, love the spectrum scope, it comes standard with 23cm & DStar, the CS-9700 is free and in my opinion you get a lot for your $2.4k compared to what we got with the 910H, 9100, 2000, etc plus options. And it looks bloody good sitting next to the 7300.

While it's not quite what a small minority expected in regards to the 10Meg ref implementation, perhaps some of the pre-release documentation or hear-say was incorrectly communicated, misinterpreted or not quite what some wanted. Either way, for those that require a highly stable rig further than what the factory specs are, I'm sure they'll find a low-impact solution, whilst still hopefully protecting the 5 year warranty. I don't participate in any of the automated weak signal digital modes - therefore any slight drift issues don't affect me - but each to their own. I applaud those that are coming up with solutions - that's ham radio - but you won't see the 9700 sitting in my shack becoming devoid of the Icom 5yr warranty.

Steve, I'll drop in over the next few weeks, we'll smoke a pipe & sip a sherry together and reflect on the birth of the IC-9700...

Cheers,

[VK3TEN]

Anyone have or come across recommended settings for an SM-30? Have the mic gain down to 10%, but still have to wispr;-)

[VK3ZAZ]

Hey guys
Keyboard warriors unite
In the RC software
Hit the memory keyer button
YOU GET
a TEXT memory 10 slots

CQ DX DE NERDSVILLE>
KKK


Does not decode though so alligators united.
You will have to consult your pilots maps.

But wait you can decode RTTY

DUH di DAH!