Do we know absolutely sure that setting a higher bias setting isn't part of product improvement? Do we know if these bias settings are identical on, say, another radio in the same lot?

We all want the latest (a 'D' instead of the "older" radio), but yet compare bias settings with the values printed in the earliest version of the service manual.

It is not unlikely that you are correct, but I'd like to know what Yaesu has to say about this. Unfortunately, the techs in Amsterdam are very carefully shielded from the outside world and you don't get to talk to them..

Geert Jan

There is a pin on the AUX connector (3.5mm jack)  of the FT897/857 that, if grounded, will cause the rig to put out a carrier.

There is a mod I wrote, published on the FT897 yahoogroups file section, which will trick the rig to switch to battary mode (20W out max) during the tuning procedure.

Combined, you get what you want I think. With my AT897, if I push the button, the power reduction etc happens automagically.

73,

Geert Jan PE1HZG

When I started doing RF work, I decided to use BNC or N for *all* RF work. These connectors, when properly installed, are so much better than the "shielded banana plug".

For the life of me I can't figure out why people insist on using plus that can only be installed by doing serious damage to the cable by overheating it.

A properly installed cable will hold the transceiver up should it fall off the work bench. As weird as it might sound, I've actually tested this. Gotta clean up some day I guess..

The only proper thing to connect to a PL259 socket is a brandname adapter to N or BNC. This adapter is part of the radio and doesn't need to be removed, ever.

Electrical parameters, as well as mechanical fit, are so much better. You'll be glad you did, really!

Geert Jan

Keep in mind that the auto electrical net will spike several hundred volts when the start motor kicks in.

You're well advised to include a filter to prevent the voltage spikes entering your radio.

Geert Jan

This is from heart as I on a train:
I assume you have the matching DC cable, yes? It�s a 4-pin molex plug with one sharp end (plus) and a blunt end (minus). The jumper you need connects the plus with the pin next to it to connect the power supply to the transceiver. You�ll need to find the plu though.

Couple of notes:
There is a small memory switch on the back. That enables the standby power supply to retain the memory otherwise it looses its settings when the power is off.

The SMPS in the 251 is a very early design and has lots and lots of issues. My advise would be not to use it and depend on an external 12V power supply. You will be a lot  better off, trust me.

Geert Jan PE1HZG

DO NOT, UNDER ANY CIRCUMSTANCE, TRY TO "ADJUST" A RADIO WITH A DEFECT!

Hence, I find the advise given by others a bit troublesome: the radio was carefully adjusted when it was in working order, by people who know the circuits, with the proper equipment, and the first thing the educated amateur community reaches to when something is amiss is a fat screwdriver to twiddle all the internal adjustments (be them software or hardware settings).

Keep in mind that a broken radio might be fixable - a misadjusted, broken radio is almost impossible to repair and should go to the bin.
If there hasn't been a reason to be in the service menus before, there is almost certainly no reason to fiddle with them now. Stay out.

Having said all that - now, how to fix your radio?
First order is to find out what exactly is happening.
Couple of things to try:

1. Your description is unclear. When you try to transmit, what happens? Does the status LED turn RED?
If repeater shift is enabled, does the display change to transmit frequency when you transmit? What's on the display anyway?

2. Do the fans start running when you transmit? When you transmit out-of-band (on a dummy load), do you get "TX Err" message?
When you transmit in-band, what is the current when you receive, does it change when you transmit, and have you tried SSB (just to measure idle current), and FM (RF output)

3. disconnect everything - everything, then just connect radio to dummy load and power supply. make sure mike is disconnected, as well as any extra things in the back. Switch to FM, press the HOME button - does the radio transmit now?
(yaesu radios block their transmitter if TX is enabled when the power is switched on - a stuck CW key locks out the transmitter, safety issue)

You'll need to do more fact finding before people can help.

Geert Jan

D-star is a closed system. The only thing your buying is a reason to buy ICOM-built transceivers; no changes are possible.

There would be an outcry if Yaesu handhelds won't work with Kenwood handhelds. Well, D-STAR is just that.

Geert Jan

When you say "all over", how much drift are we talking about?
There's two main oscillators:
- The reference oscillator, which feeds the synthesizers that create the LO and other mixer frequencies
- The sideband oscillator is separate and is pulled for CW-LSB-USB

You can tell if it's the latter because the receiver clearly will run out of it's filter -  either very high or very low pitched signals. My 747 had that problem, caused by poor contacts in the trimmer adjusting the frequency.

If it's the reference oscillator (which should be simple to diagnose), you'll need to look into that. Again, it may be as simple as oxidized trimmer capacitors.

Geert Jan

Silly answer, initially you don't adjust.

If the radio has been unused for many years, don't plug it in, you'll need to bring the radio up SLOWLY to allow capacitors to form again, and do a number of other checks. Get a local elmer who can give a hand.

If the radio has a defect, adjusting is NEVER the answer. Repairing a misadjusted radio is a lot more difficult than just a broken one.
So, make sure your radio doesn't have defects.

If the radio is well and you just need a tweak, start from the detector and work backwards to the front. make sure you understand the interaction of the AGC etc. This is not a trivial exercise.

Make sure you have the correct, good-fitting alignment tool. Under no circumstance whatsoever, use "watchmakers" metal screwdrivers because you *will* break the core of the slugs.

Slugs who have been in the same position for a long time are probably stuck. They may also be fixed by wax or something. Make sure you understand a stuck slug, and how to un-do it - it depends a lot on the material used and the situation.

On your first alignment job, keep a record of the old settings so you can undo what you did.

This all sounds tough but I've had more than a few radios that were ruined by enthousiasm. If you were close I'd invite you to do it together.

In general it's unlikely that re-adjustment will improve a radio. It's more likely something aged in time or got broken. Make sure you understand the difference, and keep your tuning tools out until you do.

Good luck!

Geert jan

You charge your handheld the same way you'd charge it in the USA, using your wall wart.

UK uses 240V, 50 Hz. There's three things to consider:

Frequency: I have never seen a wall wart that works on 60, but doesn't work on 50 Hz. Especially the newer ones (switched-mode) simply rectify the line voltage. Check the specs of your wall wart.

Voltage: Transformer-based wall warts are not universal, so you'll need a travel transformer. Switched-mode warts generally are, so you don't need a transformer, just a converter plug. Again, check the specs of your wall wart.

Plug: British-style plugs are huge and use rectangular plugs, so you'll need an adapter for that.  These are best purchased *before* you step on the plane.

So, the main question is whether your wart is compatible with 240 volts. If it is, you only need an adapter, if it isn't, you need a "travel transformer" - combination of transformer and adapter.

I should note that many "travel adapters" try to defeat the laws of physics and may not be very safe, so be careful. Common, also, are the stories of idiots who run kilowatt hair dryers off a 50-watts-max transformer.  Do your engineering work and you'll be fine.

Do get a copy of the UK band plans (as they're different - our 2m band is only 2 MHz wide), and do know how to change the shift on your rig
(1.6 MHz on 70cm), the direction of the shift, repeater list, CTCSS tones, and see if your rig can do 1750Hz as many UK repeaters need this.

Do enjoy, and frankly, you may enjoy your trip more if you don't waiste too much time on your widgets. I've done several (business) trips where the rig never came out of the suitcase - YMMV.

73,

Geert Jan PE1HZG

Your problem is probably de-sense: enough of the TX signal gets back to the receiver to open up the squelch.
A single forum message can't describe all possible scenarios.

Suggest you read up at http://www.repeater-builder.com/rbtip/ and if not suffcient, ask with the specialists there.

Geert Jan PE1HZG

You don't need to muck about with external ALC voltages at all. In fact, I recommend against it, because if the plug isn't in in full, these foreign voltages will directly go to the CPU and may cause damage, and you'll need an external battary, yeach.

The ACC plug is a stereo plug. The other pin of the plug is called 'TXREQ' and does produce a steady carrier when connected to ground, exactly what you need to tune.

I designed a small mod which tricks the FT897 into thinking it runs on battaries when TXREQ is grounded, and it automagically reduces it's output power to 20W max, irrspective of the actual power set.
When you release TXreq, original power level is restored, hence tuning is automatically done on lower power just as you want.

You can find a detailed description of the mod in the 'files' section of the Yahoogroups FT897 group, just look for my callsign.

I believe this is a much cleaner solution than what you're trying to do?

73,

Geert Jan PE1HZG

Consider running cat5 runs with only 10 mbit/sec instead of the (default) 100 mbit/sec setting. You'll find it will be a lot less noisy.

Not sure if shielding will help; these are *balanced* cable runs, that is, if you did the crimp correctly: 1-2 should be a twisted pair, so should 3-6.

Geert Jan

I had an FT920 on the bench that someone failed to repair after some similar problems.

The FT920 uses a number of PLL's and it's critical that these are within spec. On the unit I worked on, some had drifted away.

Under normal circumstances it is bad advice to tell people to check internal adjustments if they have a failure. In this particular case, I'd work through the service manual, and check (don't adjust, just check) whether the PLL's are all within spec.

Again, this is *check*, not *adjust*, for each pot you touch, note the old setting and, unless it's far off, reset to the old setting.

This does require appropiate test equipment and some experience. If you feel you're not up to it, find help from someone who can.

Again: don't try to adjust a radio that has a fault. Ever. It's unfortunately that the PLL's are touchy enough that you have to resort to this: you check, you don't adjust!

Geert Jan PE1HZG

Don't measure just volts and amps - you need to take cos phi into account. A number of manufacturers produce units that look like a time switch clock but actually measure voltage, amps, cos phi (and hence can give real watts!), but also cumulative watts and, if you give it cents/kwh, the price for running the load.
Quite a useful thing to have and mine gets loaned quite a bit.

Brennenstuhl makes them 'here, I don't know if they make a USA model.

Geert Jan