Chineese TCXO-9 for FT817/FT897

[ZL2BKC]

I recently ordered a "3rd party" TCXO-9 for my FT817 off eBay for a quarter of the price of the Yaesu original.
Being curious about all things that oscillate, I put it thru its paces and have written up a short review/report in my Blog.

http://zl2bkc.com/2014/10/29/stability- ... -in-ft817/

Bottom line is it makes a difference by a factor of 5. I hope others find this interesting.

Stability of factory vs TCXO-9 oscillator

[VK3ZTE]

Very interesting results. Since I became interested in WSPR a few months back, I can't help but have noticed the number of transceivers about that seem to drift quite severely when switching from Rx to Tx and, I suspect, similarly when switching the other way. Your results for the standard oscillator that the manufacturer supplies seems to be pretty much in line with a lot of what I have seen on air. Up to 10Hz or more, on 2m, over 2mins is not unusual - although most of that is often in the first half minute or so. The issue for WSPR is that it often means otherwise clean signals going un-decoded which is a great shame. I guess these equipments were never designed with the tight drift requirements of WSPR in mind. Your bargain price TCXO would appear to offer significant (as you say 5x or maybe even a bit better) improvement over the manufacturer's original.
cheers Grant

[VK4TI]

I recently ordered a "3rd party" TCXO-9 for my FT817 off eBay for a quarter of the price of the Yaesu original.
Being curious about all things that oscillate, I put it thru its paces and have written up a short review/report in my Blog.

http://zl2bkc.com/2014/10/29/stability- ... -in-ft817/

Bottom line is it makes a difference by a factor of 5. I hope others find this interesting.

FT817 TCXO 1.png

With an 857 and an 897 in the stable thanks for the information , most useful

[VK2EM]

Some time ago, I noticed my FT-857 was drifting when used on digital modes. I took the top cover off and discovered that the local oscillator was situated at the back of the radio directly in line with the air flow 'ventilator' holes!

I cut some polystyrene foam to form a box around the oscillator, to stop the air flow from going over and around the oscillator module, but at the same time shaped it so that it did not obstruct the flow of air through the radio.

A TCXO-9 because of its construction, would probably overcome the problem of air flow around the position of the oscillator in the radio. Time and testing will tell the story!

73 Bruce VK2EM

[VK4REX]

A word of warning, I purchased a couple of the Chinese TCXO's and found the oscillator module had been installed back to front. It was a simple fix to desolder the module and turn around 180 degrees and no damage was done.
A visual test to look for is the hole that allows adjustment should be closest to the 3 pin connector.

[VK5DF]

Hi All

I have these installed in the 817 and the 857. So far have not found any problems with them. They were easy to install.

TCXO Unit

817 Before Fitting

817 After fitting

[VK4WTN]

I have the chinese TXCO for the TS590 works really well
Wayne VK4WTN

[VK4KL]

I bought a TCXO for the Ts590 from eBay for $26. I removed the unit off the board and installed it into my TS480 works well.

Adrian
Item # 181584680150

[VK4CZ]

I was going to go the X-Ref route with my FT-817, but having read this thread I couldn't resist this as an interim measure given that these are just $22.99 incl postage!

Well the TXCO arrived yesterday, and in less than 10min of sitting down to fit it, it was installed.



I dont have the prerequisite equip to test the FT-817 performance post installation, so utilised my X-Ref locked IC-910 to do some quick comparisons.

On both 432 & 144MHz CW the FT-817 is now very close to being 'on freq' (within a KHz at 432), where previously wasn't.

I need to now run it over a long period to see if it has improved the stability.... it has previously created the typical 'bananas' on WSPR.... and drifted a few KHz each TX period when used as the IF on 2.4GHz JT65.

Hope to get the opportunity to put it through its paces shortly.

Sent from my SM-G900I using Tapatalk

[VK2EM]

I fitted one of these TCXO-9's to the FT-817 that I took to Cambodia recently. While there, in two weeks, I worked 28 countries on JT-65A, with 242 contacts. Many times, I was working a 'pileup' on 21.076MHz (my call XU7AFA), and I could see any other station on the 'waterfall' which was drifting. There were a lot, and most drifting stations were not able to be decoded!

If you are going to work any digital mode, whether on a normal band, or with the radio driving a transverter, I definitely recommend putting a TCXO-9 (or equivalent) in your radio! You won't regret it!

[VK3PF]

On both 432 & 144MHz CW the FT-817 is now very close to being 'on freq' (within a KHz at 432), where previously wasn't.

I need to now run it over a long period to see if it has improved the stability.... it has previously created the typical 'bananas' on WSPR.... and drifted a few KHz each TX period when used as the IF on 2.4GHz JT65.

Sorry all, but I was just very, very confused.....
I have never heard of this unit of measure KelvinHertz (KHz). Just how does one measure such a unit?????? As written, it represents Degrees Kelvin (absolute temperature) times frequency in Hertz.

Or is this another case of people not paying attention to the detail of a measurement system and blindly following the slack use of units and prefixes that is common in the USA where they refuse to adopt the SI system?

IFF you meant to type kHz (kiloHertz), then please let us all know that such is the case, and I will go away and occupy my time in a more useful manner.

Remember:
In the SI system (i.e. metric outside of USA and its blind and/or unthinking followers),
all of the multipliers less than x1 are in lower case,
all of the multipliers above x1 are in upper case, EXCEPT for x1000 (kilo), which is lower case, because capital K is already used as a unit of temperature - K stands for Kelvin!

You can check the detail simply - the facts are outlined on wikipedia.....

Regards,

Peter VK3PF
Scientist frustrated with people who ignore the facts.

[VK2HRX]

Thanks for the lx Peta Farad.

PS: annoys me as well.

[VK5ZT]

Leaving the nomenclature issue aside.....

I bought one of these modules for my 817. On arrival it did not work so I complained to the supplier. They were very good and promptly sent a replacement unit and lots of apologies.

THEN I saw the posting regarding the osc. module being fitted back to front and discovered that was the 'fault'. A few minutes work and the faulty unit was running and promptly fitted to my 857!

Needless to say I was even happier with the 2 for 1 deal.....

By the way they are not necessarily on frequency. Clearly the boards are not tested/aligned prior to shipping since duds get through. I had to adjust one of my units to get the radio on frequency...its a bit hit or miss as the module is fitted upside down and must be unplugged to adjust it.

Cheers

Tim VK5ZT

[VK4REX]

Hi Tim

Glad my misfortune helped someone else, it would appear this may be a batch issue or there are several suppliers.

For info, I made up a set of umbilical cables so I could operate the TCXO upside down to adjust the oscillator. I adjusted the oscillator with the radio set on 430Mhz for better accuracy.

Rex

[VK2AVR]

It's worth clarifying for those with an FT-897D that they already have the TCXO-9 fitted as standard with the 'D' version. It's only the original FT897 that needs upgrading if you want better stability.

[VK4ADM]

Just checked my FT897D, it is indeed fitted with the TXCO-9

[VK3IH]

Fitted one to my FT817 - it seems to work well.....