Copper Talk » Ask The Tech » Amplifiers » Amp on sideband? « Previous Next »

Author Message
Top of pagePrevious messageNext messageBottom of page Link to this message

Poppathree
Junior Member
Username: Poppathree

Post Number: 32
Registered: 2-2004
Posted on Wednesday, August 10, 2005 - 1:51 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I have a Magnum 257 with a Palomar250 amp in the mobile. I run the radio at minimum power to drive the amp (2 watts), works great on AM, but when I speak on sideband I can hear the relay clickety-click on and off with each word. I understand there is no carrier on sideband, but I've also been told some amps have a delay circuit to prevent this. The amp is marked "automatic sideband" with no switch for AM/sideband selection....those who hear it say it sounds great in both modes, but I don't want to damage the Palomar if it isn't working correctly,or is it supposed to work this way??.......thanx all,Lee
Top of pagePrevious messageNext messageBottom of page Link to this message

Chainsawiowa
Junior Member
Username: Chainsawiowa

Post Number: 44
Registered: 1-2005
Posted on Wednesday, August 10, 2005 - 4:21 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Probally the amps problem. Who converted it ? I had the same chattering with a brand new 500 V, I sent it back to Cali, They said who ever converted did a terrible job inside of amp. It should not click every word I would send it somewhere else other then the place you bought it from.
Top of pagePrevious messageNext messageBottom of page Link to this message

Kid_vicious
Intermediate Member
Username: Kid_vicious

Post Number: 479
Registered: 9-2004
Posted on Wednesday, August 10, 2005 - 4:46 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

poppathree, your sideband power inside the radio is turned up too high. unless that Palomar says 250"HD" on it, it's a low drive amp. turn down your SSB power to 12 watts or less, (i set mine at 10). this should cure the problem. if it happens too much though, you can damage the relay, so fix it before you key it up again.
matt
Top of pagePrevious messageNext messageBottom of page Link to this message

Sonny
Member
Username: Sonny

Post Number: 55
Registered: 5-2004
Posted on Wednesday, August 10, 2005 - 5:11 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

poppathree your not over driving the amp as far a I can tell by the info you gave Normally your side band is 3 times your dead key 2 watts dead key would be 6 watts pep also under driving can cause the relay chatter
Top of pagePrevious messageNext messageBottom of page Link to this message

Kid_vicious
Intermediate Member
Username: Kid_vicious

Post Number: 485
Registered: 9-2004
Posted on Wednesday, August 10, 2005 - 8:55 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

remember, sonny, that there are independant controls inside that radio for AM power and for SSB power.
he has his AM power turned down to drive the linear, but his linear is only designed to handle, maybe 16 watts on SSB. if he has not already turned down the SSB power then he is driving his amp with about 25 watts on SSB.

poppathree, try my suggestion and let me know what happens. you've got nothing to lose and everything to "gain". LOL
Top of pagePrevious messageNext messageBottom of page Link to this message

Chad
Intermediate Member
Username: Chad

Post Number: 375
Registered: 11-2004


Posted on Wednesday, August 10, 2005 - 9:41 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

KV the Power out on the front of the radio controlls both sideband and AM depending on what mode it's in. The inside just has settings to set relation of the front knob adjustments.

I say drive it harder. I really have to push the sideband harder on my 257 than I do AM. On AM the knob is way down on sideband it is up there. But I DO watch the output on a meter to make sure I'm not getting stupid.

Chad
Top of pagePrevious messageNext messageBottom of page Link to this message

Dx431
Senior Member
Username: Dx431

Post Number: 1080
Registered: 2-2002


Posted on Thursday, August 11, 2005 - 1:34 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I agree with Chad. The variable adjustment on the Mag 257 controls both AM and SSB. The power is to low to drive the amp on SSB. Thus you get the chattering noise. Turn the variable up till the "chatter" goes away.

Top of pagePrevious messageNext messageBottom of page Link to this message

Poppathree
Junior Member
Username: Poppathree

Post Number: 33
Registered: 2-2004
Posted on Thursday, August 11, 2005 - 7:39 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Chad, do you use a Palomar? The amp I have is not an HD model, but I do notice that when I turn the power up about 50% it chatters less. I had been keeping it at a minimum before....perhaps there is a certain threshhold of power that must be fed into the amp for the delay circuit to take effect?????? Any other Palomar people out there let me know! I might have a local tecchie with a good rep. check it out, but why put $$$ into a $79 amp, you know? Thanks again all....Lee
Top of pagePrevious messageNext messageBottom of page Link to this message

Chad
Intermediate Member
Username: Chad

Post Number: 377
Registered: 11-2004


Posted on Thursday, August 11, 2005 - 12:01 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

No, I use a KL300P, it never chatters but I do notice I have to drive it harder on SSB to get the desired power output. Leaving the front RF Out gain setting at the same spot with SSB as I do AM gets me about 1/2 the available power.

Have you done the quick tune up as posted in Lon's review? This will get your S-meter close to Power out level, well, as accurate as that meter can get :-)

Chad
Top of pagePrevious messageNext messageBottom of page Link to this message

Kid_vicious
Intermediate Member
Username: Kid_vicious

Post Number: 487
Registered: 9-2004
Posted on Thursday, August 11, 2005 - 5:38 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

chad, have you ever turned up your SSB power too high and heard what that amp does?

i too run a kl300p, and it is possible to overdrive it with my 2000gtl (volted final).

the relay chatter can be caused by underdriving the amp, but usually that produces intermittant relay clicks on voice peaks. i am assuming he is talking about relay "chatter" where as soon as you speak into the mic, the relay goes nuts.

i realize that the front panel control works on all modes, but that doesnt mean he's not overdriving his amp.
i dont claim to know it all, and there are all kinds of other reasons for this condition, but until he tries going inside the radio and turning his SSB pot down to 10watts max. and it doesnt work, im going to stick by my suggestion as it is VERY common.

poppathree, never take only one persons advice. even if it is me! LOL

chad, what do you think of your 257, im thinking of getting one for my trooper?
Top of pagePrevious messageNext messageBottom of page Link to this message

Chad
Intermediate Member
Username: Chad

Post Number: 378
Registered: 11-2004


Posted on Thursday, August 11, 2005 - 10:46 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

KV,
I am running a base setup with PLENTY of current to go anywhere... Sometimes unfortunately. As for overdrive chatter... yes... when my bench power supply was having problems with the back RF on the DC line. But now no. I can knock that amp nasty and not have chatter..... which means yes, I have listened to it from a mile away with an operator at home and know it's limits.

I hit the KL300 with 12 W and a little more on SSB, but on AM less than 2 Wdk. All reports come back well.

The 257... well.... IT ROCKS! It is now my base and has gotten NOTHING but great reports. In the truck.... IT ROCKED.

Honestly KV if you are looking for a no-frills radio that sounds great then it is the best $169 you will spend in the hobby. Just don't move it in the house... you will buy another!

Best

Chad
Top of pagePrevious messageNext messageBottom of page Link to this message

Kid_vicious
Intermediate Member
Username: Kid_vicious

Post Number: 492
Registered: 9-2004
Posted on Friday, August 12, 2005 - 12:14 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

cool! i think i'll get me one!
gonna have to wait until after my CEF fishing trip is over.
Top of pagePrevious messageNext messageBottom of page Link to this message

Poppathree
Junior Member
Username: Poppathree

Post Number: 34
Registered: 2-2004
Posted on Friday, August 12, 2005 - 12:59 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Hey KV, it was just clicking on each word as I said, not going nuts with chatter, so maybe I'll drive it a little more........I've heard an amp go nuts on AM when overdriven and thats not what this did.Anyway, not to beat a dead horse so to speak-thanks again for all your help (everyone!). The Magnum truly is a sweet radio and I have no complaints about it at all........but..... maybe I'll put a larger diameter knob for the clarifier, it's a little sensitive, especially when mobile.....hmmmmm.......does it ever end??lol!
thanks again,Lee
Top of pagePrevious messageNext messageBottom of page Link to this message

Chad
Intermediate Member
Username: Chad

Post Number: 379
Registered: 11-2004


Posted on Friday, August 12, 2005 - 8:56 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

If you are talking about the Midwest gathering then you may want to order from Lon? They are going down before the meet and getting goodies. May save you some S/H!

Chad
Top of pagePrevious messageNext messageBottom of page Link to this message

Kid_vicious
Intermediate Member
Username: Kid_vicious

Post Number: 496
Registered: 9-2004
Posted on Saturday, August 13, 2005 - 8:18 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

sadly chad, i wont be able to make it to the gathering in OH. im just too far away. the GF and i are taking a trip on that weekend up into the mountains and we will hopefully get to talk to the members there.

Add Your Message Here
Post:
Username: Posting Information:
This is a private posting area. Only registered users and moderators may post messages here.
Password:
Options: Enable HTML code in message
Automatically activate URLs in message
Action: