Video: IC-9700 VHF/UHF/1200 MHz Base introduction

Transceiver mods, fixes, issues, reviews
VK3OE
Frequent Poster
Posts: 139
Joined: Fri Nov 21, 2008 3:30 pm

Re: Video: IC-9700 VHF/UHF/1200 MHz Base introduction

Post by VK3OE » Sat Apr 06, 2019 12:16 pm

Hi Roger,

It does indeed look like the 10MHz ref input is only a reference to adjust the internal reference frequency, Page 13-3 of the IC-9700 english manual does apparently show this, but little detail is given.
The basic manual in English is at:

http://www.icom.co.jp/world/support/dow ... RD=ic-9700

The frequency stability spec is;
Less than ±0.5 ppm (–10°C to +60°C, 14°F to 140°F) or +-650 Hz at 1296. :thumbdown:

There is more information in the Advanced user manual on page 6-3, the English manual is from:

https://www.hamdigitaal.nl/download/alg ... _ENG_0.pdf

which confirms this opinion.

Very disappointing!!!
Last edited by VK3OE on Sat Apr 06, 2019 12:38 pm, edited 1 time in total.
Andrew
VK3OE/VK3OER
Science = hypothesis >> measurement >> Theory

User avatar
VK4GHZ
Forum Diehard
Posts: 1841
Joined: Mon Jul 04, 2011 10:39 pm
Contact:

Re: Video: IC-9700 VHF/UHF/1200 MHz Base introduction

Post by VK4GHZ » Sat Apr 06, 2019 12:26 pm

VK3OE wrote:Hi Roger,
Very disappointing!!!
Not surprising, given the odd internal reference frequencies these radios can have.

This method should offer better phase noise characteristics if it is steering another ref osc though.

Vs some PLL running at ridiculously low PD steps to multiple up to whatever is needed.

Sent from my SM-G970F using Tapatalk
Adam, Brisbane
http://vk4ghz.com | VK4GHZ on Youtube
Image Waiting for the perfect 2/70/23 multi-mode SDR transceiver

User avatar
VK3HZ
Forum Diehard
Posts: 464
Joined: Sat Apr 02, 2005 4:52 pm
Location: Melbourne, Australia
Contact:

Re: Video: IC-9700 VHF/UHF/1200 MHz Base introduction

Post by VK3HZ » Sat Apr 06, 2019 12:48 pm

A fractional PLL would do the job OK and as it's still using the OEM reference oscillator, there would be very little, if any, impact on the phase noise characteristics.

I think they had the Vac student working on this!

VK1JA
Forum Diehard
Posts: 351
Joined: Tue Sep 14, 2010 9:50 pm

Re: Video: IC-9700 VHF/UHF/1200 MHz Base introduction

Post by VK1JA » Sat Apr 06, 2019 1:36 pm

It is disappointing. In stock form it may not have good enough stability to be used on most the weak signal digital modes.

There has been talks on one of the iogroups that looking at the service manual that it appears that the hardware is there for the LO to be locked to the ref freq, so it may be a matter of a firmware update to have the option available. Early days yet!

The link below shows whats under the covers of the IC9700. You'll notice in the pictures lower down the page quite a few pigtails with ufl(?) connectors. Lets hope that one of those is for the LO, rather than having to hack the board to inject a stable freq.

https://demenzradio.blogspot.com/2019/0 ... 0.html?m=1

Also notice that there are 6 pigtails in a row, the pictures are a bit blury but it would be interesting if these could be an easy solution for a separate rx/tx lines, or IF output for a bigger pan adaptor display :)

User avatar
VK4GHZ
Forum Diehard
Posts: 1841
Joined: Mon Jul 04, 2011 10:39 pm
Contact:

Re: Video: IC-9700 VHF/UHF/1200 MHz Base introduction

Post by VK4GHZ » Sun Apr 07, 2019 7:45 am

I'm unlikely to be invalidating a 5 year warranty with mods any time soon!


Sent from my SM-G970F using Tapatalk
Adam, Brisbane
http://vk4ghz.com | VK4GHZ on Youtube
Image Waiting for the perfect 2/70/23 multi-mode SDR transceiver

VK1JA
Forum Diehard
Posts: 351
Joined: Tue Sep 14, 2010 9:50 pm

Re: Video: IC-9700 VHF/UHF/1200 MHz Base introduction

Post by VK1JA » Sun Apr 07, 2019 8:28 am

Me either, just not worth the risk.

Hopefully it can be implemented in a firmware update, or at the most a case of unplug a cable and plug in a different ref source, similar how the IC7300 has the IF tap.

Post Reply