Ham Radio Forum

Hi all
My name is richb, I just accuired a Pride DX-300 RF AMP, Im trying to see if the amp will work with my TS 530SP rig. The amp needs ~10 to 12 watts to give the full rated output of 1KW. The TS-530SP will do 100+ thats a few watts to many. I don't want to distroy the amp or my rig. Does anyone know if it will work and any info info on how to do it will be appricated. also the rig has a acc jack but the amp does not.

Thanks
richb

Hello Rich.

I'm a bit surprised that you're asking about the PRIDE DX-300 RF Amplifier considering that you hold an Extra Class Amateur Radio License. Most of the hams I know that hold an Extra Class Licenses are very strong on Electronic Theory and Circuit Design but I guess not in your case.

The PRIDE DX-300 H.F. / RF Power Amplifier is nothing more than a modified Citizens Band 11 Meter / 27 MHz RF Amplifier (Illegal use in the U.S.A. on 11 Meters).that will cover 3 ~30 MHz. The RF Amplifier employs a single 4CX250B RF Vacuum Tube that will produce between 300 ~325 RF Watts Output in the Class AB1 Linear Mode. It produces only a +3.5 ~ 4 dB Gain difference compared to your Kenwood TS-530SP 100+ RF Watts Output a rather small signal change of RF for the person on the receiving end.

This is a Grid Driven Input therefore requiring a very low RF power to be fed to the Input circuitry 5 ~ 10 RF Watts Maximum and "if" you chose to use the TS-530SP 100+ RF P.E.P. Watts Output into the Amplifier's Input circuitry, you would burn up the electronic components producing maximum smoke.

To connect your TS-530SP transceiver correctly to the PRIDE DX-300 RF Amplifier, you must purchase or build a 10 dB 50-Ohm 100 Watt Coaxial Attenuator and modify the electronic circuitry on RL1 Pin #13 & the T3 Center Tap 9 to 1 RF Transformer therefore dropping the 100+ RF Watts P.E.P. Output to 10+ RF Watts P.E.P. Output being just enough to Drive the RF tube's Grid Circuit and not attenuating any receive signal. Refer to the manual's Schematic on Page # 32.

Here's the PRIDE DX-300 On-Line PDF Manual / Schematic Link:

http://www.cbtricks.com/Amp/pride/dx300/graphics/pride_dx300_mauual.pdf

I hardly think it's worth your time and effort to perform this nodification because you must increase your RF signal a minimum of +6 dB Gain to see a 1 S Unit change in the receiving end signal.

Good Luck!

73,

Dan
WA9WVX
40 Years as a F.C.C. Licensed Amateur Radio Operator.
38 Years as a F.C.C. General Radiotelephone Operator Licensee (Formerly a 1st Class Licensee in 1971.

AWWWW.....Hoooey! Richb asked for help. What he got was the typical "Master Ham" type reply that turned me away from amateur radio (for the second time!). What surprises me is that a (claimed) 40 year radio vet would not pick up on a fairly new guy asking for help with a "Boatanchor" type hybrid radio. Most younger hams have never used a vacuum tube rig and need a little assistance. The TS-530sp has 6146b's in the final. It is a fine old rig. It DOES NOT need an attenuator to reduce power for that Pride 300. What you do is look on the back of the rig for a 7 pin DIN plug. Pin 6 is the ALC connection. The alc will reduce the power out to almost zero watts if connected correctly. Now - You need a 9 volt battery and a 1000 ohm pot. The alc works off of negative voltage. Ground the positive terminal of the 9v batt with the 1000 ohm pot in series with the negative terminal of the battery to pin #6 on the "remote DIN connector" Use the center pin of the pot for one connection and ONE of the outside terminals for the other. Now you can adjust the new ALC control from 0-9 volts. (check it with your multimeter first and be SURE to put only negative voltage into the radio) Tune up first time into a dummy load (or your antenna) on CW with ZERO volts on the ALC pin. You should see +/- 100 watts out. Hold the cw key down and adjust the new ALC control for 8-10 watts output. Now you've got a grip on the tune-up procedure. No other tuning should have to be done to the rig as it is designed for tube-type linears. Switch the rig to standby, Connect the Pride to the rig and warm it up 20 -30 mins.. Switch the rig back off standby. Using the CW key tune the Pride in AM mode for max smoke (output). You should use a wattmeter in between the rig and the amp to keep your eye on everything. A cheeep Radio Shack $20 buck meter or a truck-stop special that will read to 100 watts will do the job. Switch the rig to SSB and the Pride to SSB. With the Pride on standby check your output again by keying the mic. If still good we're ready to go. And don't believe the 1 S-unit Hoooey either. You can vary the ALC control if you need to. NOW - make a contact. Tell them you're checking an amp and please give you a sig report and S-reading. Switch the Pride to standby and crank the Kenwoods ALC back up to see 100 watts or so out. Ask for another sig report. Note the difference. If the Pride is working as it should you should see a significant increase in the sig report (more than 1 S-unit!)with the amp in line. I have found the CB amps work well on SSB if not over-driven. There we have it - 'nother unlegal cb leenyar on HF! And all for the cost of a 9 volt battery and a 1000 ohm rat shack potentiometer. I used this with my TS-830 (it had 6146b's in it also) and it worked well with a (Shame,Shame!) Maverick 250 and a Thunderbolt 305. But I may 'uv bin on sum dem 'nuther bands most Hams despise so much.......

One other thing - the Pride has an RF sensing circuit and will key up when it senses the transmit rf from the Kenwood. It does not need to be connected to the radio except inline with the antenna coax. Have fun and tell your ham buddies its an old Heathkit SB-200. - '73 - Max