IRET PRC247-B

[DL9QQ]

Hello all,

I get a PRC247-B in the last days. My first IRET radio now.

Radio is without Handset and now I have to fit a Handset for the radio. I found only a manual for the PRC247-A on radionerds.com
The PRC247-B is more different than the older PRC247-A. The connectors for Handset are not the same as on the PRC247-A. I can use the connectors from the RFT SEG15D for my PRC247-B

Has anyone here in the Group the pinning for these radio or a service manual?

I can add more pictures when needed.

Thanks in advance and happy easter.

John
DL9QQ

[IK0MOZ]

Hello John, congrats for you new set. I never seen the PRC-247B and noted that the lettering is in italian language. I have the A type (panel in spanish) and are very sadisfied about the performances. I have the problem for the manual, following your post i checked on Radioneds site
but not found it, probably for my fault. Please can you give me the link ?
Hope some friend will solve AF the connector pin out
Ciao and happy Easter to U and family - Mario IK0MOZ

[DL9QQ]

Salve Mario,

here you have the Link:

http://radionerds.com/index.php/IT~PRC-247A

This must be the version that you have.


There is a Seller on ebay, he is selling stuff for the PRC247:

http://www.ebay.de/itm/IRET-IF-SSB-BOARD-FOR-PRC-247-HF-SSB-TRANCEIVER-NOS-/261148116234?pt=LH_DefaultDomain_0&hash=item3ccda4050a

He is selling the battery for the radio too.

Ciao,

John
DL9QQ

[IK0MOZ]

TNX John, I get the manual. This is for VRC and GRC type that seems to be different from the PRC. My set (PRC) for whip antenna has an internal motorized ATU, while the type in the manual use an external ATU same as your set. Anyway usefull. Ref the Audio connector belive me you are lucky because the connector used on 247-A is pratically impossible to find while the SEG type is more popular. You can test this possibility:
On PRC-247A :
1 - GND --> for SEG connector should be pin A
2 - PTT --> should be pin B ...... and so On
3 - Remocom
4 - In Dinamic micro 200 Ohm
5 - Key
5 - Out Audio 200 Ohm
7 - In Carbon micro
Let me know - MFG Mario

[DL9QQ]

Salve Mario,

thanks for the information.

You write that the PRC247-B that I have, is without built in antenna tuner. I opened the radio and here are more pics of the radio inside. The radio is fitted with built in antenna tuner.

[IK0MOZ]

Very interesting, but totally different from 247-A. In my case pushing the "SINT" button (Tuning) starts an inside motor and looking a tuning table (Position/Frequency) is possible tune the antenna for all frequencies range. This procedure is valid only for whip antenna. In case of use 50 Ohm output the indication must be on 100 (no coil). Your set (B type) have the SINT button that probably switch with the help of relay the antenna coils, but in case of 50 Ohm output ? Mario

[roberto burdese]

Hi John, PRC-247B, This is really a news. I suppose it has been one of the latest productions. Very interesting and never seen in Italy. Roberto "BR"

[IK0MOZ]

Hi John, looking better the front panel of your set I noted that on the right side of the SINT button there is a rotary switch marked STILO - 50 Ohm. STILO in italian means WHIP so if you use a standard wire antenna (dipole) this switch must be on 50 Ohm position and antenna connected on BNC while if you use a whip using the big socket the same switch must be on STILO position and probabbly only in this case the tuning system is active. Interesting to know what happen when you push SINT and the way to understand that the antenna is tuned (Max instrument indication ???)
MFG - Mario

[DL9QQ]

Hello all,

I tried first to find out what pin of the connector is Audio Out, correct it is pin F, Ground is pin A. I connected an antenna to the BNC socket and switched on the radio, now I can hear noise from a 200 ohm speaker connected to pin A and F.
I selected a frequency, where I can hear voices from amateur radio ( checked for activity with other radio. But from the PRC247-B, I can not receive any station, only noise from the speaker . I triede to receive a broadcast station, nothing to receive. The antenna switch is still in position 50 ohm.

At the next step I tried the whip connection, antenna switch to stilo. I connected a long wire to whip antenna holder. The same result, nothing to receive .

Switched antenna selector back to 50 ohm and connected a power meter with Dummy Load to the BNC Socket. I pressed the Sint button and can hear the side tone in the speaker and a relay switching but there is no output power from the PA stage .

In the radio are many tantalum capacitors. I know they are very problematically parts in older electronic equipment.

Has any one here in the group an Idea what to do now. Should I replace all tantalum capacitors?

I am still searching for a service manual or circuit diagram for this radio.


John
DL9QQ

[IK0MOZ]

Ciao John, I guess that the test of power output must be done Key down or with the PTT pressed. I have some sheets referred to troubles shooting to identify the possible fault module testing the DC on Test points. I have only to look for it in my papers (no simple....). Give me a couple of days and hope to find them.
Mario