rf gain wat is het en hoe werkt het

[19AC393 gebakje]

wie kan iets meer vertellen of heeft links over rf gain
heeft rf gain alleen invloed op bv het ontvangst gedeelte of alleen het zend gedeelte , mischien wel allebij
wie kan iets meer vertellen ??
ik moet namelijk voor mijn nieuwe eind tor voor mijn president de gain bijstellen , en aangezien ik niet op de hoogte ben van rf apperatuur ( ben wel elektro monteur ) zoek ik dus informatie over hoe ik hem moet bij stellen , en hoeveel , en vanwaar ik de waardes kan meten ( controleren ) en welke deze zou moeten zijn
het gaat hier dus om de nieuwe mrf 497 tor van 50 watt

[19DT2120]

Ik hoop niet voor je dat je hem al hebt want volgens mij kun je ook een SD 1446 gebruiken met een iets mindere gain maar kost bij http://www.sec-digital.de/ €20,-

update :sorry ik zag dat de mrf497 een gewone tor is en de SD een vlinder tor

Ik zit zelf ook nog te zoeken naar een vervanger,maar ben er nog niet uit.Hij moet betaalbaar zijn,anders hoeft het voor mij niet.Ik heb hier nl ook nog een andere set staan die is van zich zelf al 100W.

extra update:

Code: Selecteer alles

MOD 1
When using a power mic with the HR2510, with the ALC cranked up, you will
Overdrive the Final. Two Solutions exist, Keep the ALC turned down, or
replace the final (MRF477) with a MRF497. This will cure the overdrive problem.
To pull a few more watts from the HR2510, you may replace the pre driver ,
Q134 (2SC2086) with an ECG or NTE 340. The 340 pin outs are opposite the
2SC2086 (the 2SC2086 is BCE and the 340 is ECB). Set the bias with VR112 to
70 - 80 Ma  in USB on 28.000 MHz with a 1kHz tone and the ALC set to peak.
--
MOD 1a
This is an improvement on MOD1. This suggests you change the MRF477 with
the MRF497, making the necessary Bias adjustments. (as in MOD 1). Then instead
of changing Q134(2SC2086), you modify the circuit to provide more Gain.
See \"The Better High Power Mod\" page for more info.
--
!!!!!ATTENTION!!!!!
The following mods [Mod 2 & Mod 3] WERE missing some 'Key' information.
With the help of a few of you out there we have solved the problem.
Thanks, Rogerbird
--
MOD 2
This will cure the overdrive problem and allow you to pull a a few more watts also.
The MRF477 may be replaced with a MRF455, But since it is not a TO-220
case a mounting problem exists. A piece of aluminum, 1\" wide by 2\" long by 1/16 \"
thick may be used to mount the MRF455, Then your new heatsink may be mounted
to the chassis heatsink underneath the circuit board. Small pieces of hook up wire
must be used to connect the circuit board leads to the leads of the MRF455.
The SECRET to make this work is to STRAP the Emitter of the MRF455 to one of the mounting screws.
With the help of several people, we have found that Uniden is using this
method to cure the problem I had before.
I have found in some radio's you may need to add or change
some of the coupling capacitors to get nominal output,
But, overall this mod is cheaper than the MRF497 mod and more robust!
I have even been able to mount the MRF455 directly to the rearpanel.
Just mark and drill 2 holes to mount it.
Also for a Bias Diode you can use a 1N4001 diode, Just make sure it
is in contact with the ceramic of the final to detect its heat.
This final set-up will last forever.
--
MOD 3
To double the output power you must make a new circuit board, 1\" by 2\",
that will accommodate two final assemblies (using two MRF455).
Remove Q132, C124, C125, D164, R157, VR112, L126 and R180.
Order Duplicate parts from Uniden Parts Department.
9900 Westpoint Drive, P.O. Box 5043,  Indianapolis, IN 46250  Tel.#317-842-1036.
         The Uniden part numbers are:
         Q132 - BDBZ0529001
         C124, C125 - BCCG815615Z
         D164 - BDFY0058001
         R157 - BRFT611004Z
         VR112 - BRTY0182101
         L126 - BLDY0221001
         R180 - BRFT614704Z
The new circuit board assembly  (both new finals) must be attached to the radios large
finned heatsink. Use hookup wires to attach the input, output and ground leads of your new
board  to the junction of C126 and R180,  R158 and L135. Study the schematic carefully,
duplicate both final assemblies as per schematic. Double check everything. If you don't have
a service and repair manual, Order one through Uniden Parts.
--
The HR2510 uses low level modulation so it will never be as loud as a radio using high level
modulation (on AM only), but by turning up the AMC, and the previous mod they become
AM performers also.


[19DT2120]

HR2510 Mods
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This page has various modifications for the HR2510 / 2600 / Lincoln



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The origional Final for the HR2600 is the MRF477.
It can produce about 40w.

But if you want more power, you can replace it with the MRF497, which will boost you up to about 50w or so.

Now, the origional driver is the 2SC2166.
You can boost it some more by going back down the RF chain to the TX buffer and replace the 2SC2086 with a 2SC1973. The leads are backwards, so beware.

You should also beef up the wiring and traces between the power connector and the final.
It is also a good idea to put a large electrolitic cap inside the radio just after the power connector, a 4700uf would be good if you can find a 16v-25v one that will fit.

The leads on the 2SC1969 and the 2SC2312 SSB finals are not the same as the MRF477-MRF497, so a swap is not recomended, and you will also loose a lot of output. The 2SC1964 has the same lead configuration, however, but it can only produce about 20w or so.