Galaxy DX 959 question VR14/VR18 question

[Auxarcs]

Hello. New here, but I've been doing a bit of reading and am curious about the DX 959 mod that increases the RF power. It is my understanding that VR14 and VR18 are needed to be adjusted to see the improvement. With that being said is that all that is required to see the power increase?
Thanks

 

[Robb]

<Remember; these adjustments are for the low power/high power settings of the RF Power output knob on the face of the radio.>

Just set it to the 1 watt setting when the RF Power knob is fully CCW with VR 18. Then turn the RF Power knob fully CW and adjust VR 14 for the high power setting of 4 watts.

Be sure to turn the Mic Gain knob fully CCW before you adjust either VR.

I hope you aren't considering trying to get more power out of the radio than it was designed to put out. If you crank it up too high, two things will happen. The first thing is, you will lose your 4:1 ratio of dead key watts to peak watts. This will make it sound lame on AM. I wouldn't do it!
Second thing is, that you will be pushing the output transistors harder and cause them to fail prematurely. I don't make the rules; I just understand why they are there . . .

http://www.cbtricks.com/radios/galaxy/dx959/dx959_trans_adj.htm

You might be able to turn up the ALC//SSB output a little bit. And I mean, just a little bit too! That will be VR 13. You can turn it up from 12 watts to about 18 watts. To do this, you will turn the Mic Gain all of the way up/CW, turn the RF Power knob fully CW, and then key the mic on SSB/LSB and say "auuuuuuuuuuudio" evenly - and then turn VR 13 up until you see about 18 watts on your external power meter and dummy load or antenna.

What? Don't have an external power meter? Then; don't do any of this. Save yourself the trouble! If you want more power out of the radio; then buy a cheap 100w amp for around ~$50/used and that is how you do that right.

I've aligned a few of these radio, and they are OK radios if they are adjusted correctly. If you don't have the experience and the equipment to do it yourself; then take it to someone that does.

Ciao!

 

[Auxarcs]

Thanks for the heads up on that. I haven't bought one yet but am looking to buy a rig I can play with a bit. I have also been told that these can sometimes get a bit out of wack and need readjustments. Not too sure on that though and I am sure that mileage may vary, but just trying to get an understanding before I jump in. My swr and power meter is on its way. Thanks again.

 

[Robb]

Thanks for the heads up on that. I haven't bought one yet but am looking to buy a rig I can play with a bit. I have also been told that these can sometimes get a bit out of wack and need readjustments. Not too sure on that though and I am sure that mileage may vary, but just trying to get an understanding before I jump in. My swr and power meter is on its way. Thanks again.

Yes, and they do respond very well to a proper alignment/tune-up. All of the ones that I have aligned have gone from being a pooch to a gem. The nicest thing about a Galaxy - including the 959 - is the receive/transmit audio sound and sensitivity. The worst thing about any Galaxy radio, is that they drift off frequency in SSB mode.
Drift like a boat on a windy lake . . .

They are known for their ability on AM; and drifting isn't a real problem for that mode.

The best thing that a dealer of Galaxy radios can do, is give them a full alignment. A REAL alignment. Not just a ear test of the radio, and then just shove it back in the box and ship it off to the customer. That just won't do; especially for Galaxy radios.

These radios have a lot of potential - IMO. If they would just put in better/more stable crystals for the oscillator circuits; they would be worth something. But it needs at least two high stability crystals, and they are about ~$15 apiece. This would raise the unit price of radio, and make them harder to sell and compete with other mfr's.

Should and can they do it?
Yes.
Will they?
Humppphhh . . .

The best way to deal with this 959 radio situation, is to get one used at a low price. Then, have a shop replace the 2nd and 3rd crystals with the high stability crystals, and then have them give the radio a full alignment.
Then; SSB will work well enough to call that radio 'a keeper'.

But if you want to use the radio on AM and sound loud; then get a ~200-300 watt linear and a really decent antenna. A great power mic too. That is what you are looking for; isn't it? If SSB is the goal; then put up with the driftiness of this radio - or get a RCI-2950DX or a Magnum 257. It is a question of how much you expect from your radio.

I use a Galaxy DX 99V/Export in my car 100% of the time (usually on SSB too).
Like the receive and transmit; hate the SSB drifting . . .

 

[n0zna]

i have one,great radio.73s de JW

 

[Auxarcs]

But if you want to use the radio on AM and sound loud; then get a ~200-300 watt linear and a really decent antenna. A great power mic too. That is what you are looking for; isn't it? If SSB is the goal; then put up with the driftiness of this radio - or get a RCI-2950DX or a Magnum 257. It is a question of how much you expect from your radio.

I like getting stuff I can use and play with a bit. If I wanted to mess with the wattage; I would have that option. But something to use, tweak, try to make it run the best it can. I use to get certain brands of motherboards and chipsets for computers so I could overclock them and squeeze out just a little more speed just to say I could. This is a new area for me and would like jump in with something that is good as-is, but can be better. If it starts out "twitchy" that can make me nervous because I would be sure if it was a piece of junk or if it just needed something tweaked that I don't know about. So I am in the "read up about it" phase of figuring out which part of the creek I'm jumping into.

 

[Robb]

I like getting stuff I can use and play with a bit. If I wanted to mess with the wattage; I would have that option. But something to use, tweak, try to make it run the best it can. I use to get certain brands of motherboards and chipsets for computers so I could overclock them and squeeze out just a little more speed just to say I could. This is a new area for me and would like jump in with something that is good as-is, but can be better. If it starts out "twitchy" that can make me nervous because I would be sure if it was a piece of junk or if it just needed something tweaked that I don't know about. So I am in the "read up about it" phase of figuring out which part of the creek I'm jumping into.

Believe me; I can fully appreciate what you are saying - especially about tweaking with things. Even computers, as I do that too - still. But radios are a bit different from computers. They have different needs and requirements. The best tweaks are in the receiver; not the transmit. In the audio sound of the transmit perhaps; not the power output. Power is left up to the external RF amps. So, we don't need to squeeze the last 1/10 of a watt of RF power. Because even 1 watt or 5 doesn't make a difference that can be detected by a receiving station. Oftentimes, we have turn the power DOWN to make it match the input requirements of the RF amps! WE need radios to be stable, clear, sensitive, and reliable. To that end, tweakers learn the tricks and make their moves

You might want to consider your expectations and goals. I think that you are probably a motivated person, just accept that a course correction might be needed is all. But don't take my word for it; hang around awhile and see for yourself. Starting on the 959 will be a leaning experience. Perhaps you will be the guy who can get it more stable on SSB than me or anyone else. Just share it with me when you do; OK?

You will need equipment to tweak. A 50mhz oscilloscope, an accurate frequency counter, a reliable digital multi-meter, RF signal generator, dummy load, accurate power supply, and an accurate power/modulation meter. Accuracy is the key word here. If you like that; then tweaking radios will become easier and easier for you - IMO.

Not to mention, you have a bunch of guys on this forum that know radios/antnnas and can give some real pointers. Still learning myself - BTW . . .

 

[Auxarcs]

Sounds like fun... and a good start on a shopping list! Thanks for the help and info. I'll do a bit of a course correction and hopefully come out with better results.
Do you think the 959 is a good place to start or is there a better starting off point?

 

[Robb]

One might say that starting off with an AM only radio is a better place to start. But I started off with the Cobra 148 GTL. This SSB classic has plenty of mods and info online, not to mention that I have about 1/2 dozen of them in my collection. I thought it would be the better place to start to learn. But the 959 is also a great place to start too.

There are frequencies you can add to it. There is a mod to 'unlock' the clarifier. You can put Shottkey 1N6263 diodes/Sanyo 2N2999e into the receive circuit to milk better receive out of it. But one of the best things for it, is quality and careful alignment to get it to perform as it should. You might even consider putting a "TopGun Compressor" in the mic circuit too. That would make it finer still. Not to forget, that the crystals mentioned above would be a very important mod to keep it on frequency when using SSB mode.

Maybe you will find more . . .

 

[crazy_cooter]

ok this radio is a variable power radio, so you have to be careful turning things inside of it. VR18 is your low power adjustment, and VR14 is your high power. Turn your RF power to max, and then adjust VR14 to your desired power setting. Next, turn the RF power knob down, and adjust VR18 to your desired low dead key. I would say 2 watts minimum. And probably no more than 12-15 watts max with the RF power on its highest setting.

 

[Robb]

Two watts on the lowest setting would be just fine for this or any radio that has the variable power knob/function. Some guys will set the low setting to 1 1/2 watts for even better AM performance with a linear. Some even go as far as 3/4 of a watt and prefer it.

However, setting the high setting to 12-16 watts is just too high. The best way to do it for the high side, is to turn it up and then check to see that it still preserves the 4:1 ratio of dead key watts to peak envelope power watts. Certainly 12 watts won't work with that in mind. The recommended settings from the tune-up info does - however - work optimally. Been my experience. In some cases you might eke out a watt or two more - if it has a MOSFET final - but a few extra watts won't really make it work any better and begins to tax the final more than it is worth - IMO . . .