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Re: 27.560 muppets

Posted: 03 Sep 2017, 21:06
by ch25
Sorry mate, you have no idea what you are talking about.
3KHz spacing on SSB is enough for my rig to have clear frequency.
I can work DX even with someone transmitting 1-2KHz from my RX frequency. Some splatter, but workable.
Get decent radio, you'll know what I mean.

Re: 27.560 muppets

Posted: 03 Sep 2017, 21:11
by ROTEL240
ch25 wrote:Sorry mate, you have no idea what you are talking about.
3KHz spacing on SSB is enough for my rig to have clear frequency.
I can work DX even with someone transmitting 1-2KHz from my RX frequency. Some splatter, but workable.
Get decent radio, you'll know what I mean.

Be interesting to know what your radio and filter settings are matey.i don't tend to have to many splatter problems it's only the big kW power stations that give me a slight knocking when 5 kc either side

Re: 27.560 muppets

Posted: 03 Sep 2017, 21:30
by ch25
It is irrelevant. RX performance matters. SDR or crystal filters.

Re: 27.560 muppets

Posted: 03 Sep 2017, 21:47
by LeakyFeeder
NightProwler wrote:Im using a Yaesu FT757GXII with an Imax 2000 fed with 15 meters of RG213 not a Fidelity 1000 and a coat hanger :roll:


Coff coff!

Naff all wrong with the legend that is the Fidelity 1000 mega rig.... ;)

Re: 27.560 muppets

Posted: 04 Sep 2017, 00:28
by wa10
You will get QRM when we have people using RF amplifiers like a guitar amp driving kl203's 400's 500's & equivalent zetagis with 20w ssb,

5kc is enough for j3e (normal ssb) if people keep their IMD to sensible levels,
But they don't, The reality is ops who use amps like jimmy hendrix & eSSB voodo so its not enough.

Re: 27.560 muppets

Posted: 04 Sep 2017, 19:37
by NightProwler
Tim wrote:You can quote figures all you like, you're going to get splatter from 5kc's either side no matter what the radio is, old or new.


Exactly :thumbup:

Re: 27.560 muppets

Posted: 05 Sep 2017, 06:45
by Bigdave
Here's some figures for you to consider, I'm thinking your definitely going to get splatter.................... :lol:

Re: 27.560 muppets

Posted: 05 Sep 2017, 14:37
by speeddemon
:shock: :wtf: :lol: :lol:

Re: 27.560 muppets

Posted: 13 Sep 2017, 06:03
by Unit 148 Mobile
wa10 wrote:Traditionally the Italians were well known for overdriving amplifiers creating IMD that causes issues to near by frequencies, they often used class C amps on ssb too.

Its not all their fault nor are they alone in thinking pumping 20w ssb into cb amps is ok because it says so in the user manual,
the manufacturers also put ssb switches on class C amps which is almost as stupid as claiming up to 4x what the amplifiers will output with reasonable IMD levels,

there are no specs to meet for cb amps so they can claim anything to lubricate your wallet.


I'm not so sure about the Italians using class-C amplifiers on 11m frequencies.

While many Italian amplifiers may not have the best bias circuits they do in my experience have them so it's not just a delay that is switched on with the AM - SSB switch.

I think you'll find that it is the 'competition' amp's produced in the US that are run 'flat out' in C. They are manufactured like this.

If you know of any Italian 27Mhz CB amplifier without bias please do tell. Sometimes I need educating.

The fact of over-driving amplifiers is of course a different subject and I agree totally with you but if you've ever listened to UK signals while abroad then you'll know that there is little difference between this country and Italy.

Possibly they have more and bigger amplifiers but the sound across the band, especially around 555 is the same.

I agree with ch25. It's important to have as good a receiver as you can afford when investing in a transceiver, good receiver selectivity is king and will in most cases, Jimmy Hendrix or not, allow you to pull out those weak and often rare DX. If you can hear them but they cannot hear you then it's a simple antenna upgrade, and if that doesn't work...you know me.

Unit 148 Mobile (Now based in 5B4 land)

Re: 27.560 muppets

Posted: 13 Sep 2017, 08:54
by Admiral
You can argue until the cows come home about xKhz filters and dirty amps, but it's still good operating procedure to QSY to at least the minimum that the band and equipment were designed for, in this case 10Kc.

Re: 27.560 muppets

Posted: 13 Sep 2017, 16:49
by KlondikeMike
You should be thankful that they moved off T5. The further you move away from your initial contact frequency, the less likely they are going to be there after you move. Sometimes a 20khz shift might be too much.

Re: 27.560 muppets

Posted: 13 Sep 2017, 19:24
by speeddemon
Back in the day Italian cb'ers loved fiting/using these in ther old alan 48's/colts mky8000 :geek: :thumbup:

Re: 27.560 muppets

Posted: 14 Sep 2017, 21:34
by wa10
148

The standards of audio on 555 has gone down the pan so i can imagine what you say is correct, i hear folk that sound **** local getting r5 reports from people who's ears don't work right,

Zetagi Bremi CTE solid state amps ALL sounded like they had no bias on ssb even though some of them did have basic bias circuits,

later amps have a very similar crude circuit but it works better, still unregulated starts out too high & dips back towards class C as drive level increases but its enough to cover up audible switching distortion,

more recently we had CTE bipolar & fet amps with ssb delay in class C, Zetagi, rm, ea150 clones, kl300's, that were class C with ssb delay switches, some ea150's did have biasing and some did not,

more recent zetagi 150's use the kl203 fet board which is biased but FAR from linear above about 4w drive,

fake palomars that say AB on the front but are class C inside and unstable,
a palomar elite 400hd makes a USA comp amp sound clean,

ebay palomar 600-900's that do have untracked regulated biasing but are half ass built & not tuned, i was so impressed i sold the 4 x 2879's that came in my 900v,

some of the latest RM cb amps have active regulated biasing with thermal tracking based on the motorola 723 regulator circuit,
i have not tested them for load regulation but i have two to repair so i will test the bias circuit,


i am familiar with the Davemade clones Joemade Xforce Fatboy, they do sound crap on SSB and not so good on AM to my ears unless you bias them,

i have seen the crude class B biasing that Xforce used when Carl was the owner & Danny worked there,
don't know the new guy Harlan or seen what they are using for biasing now.